Physics in Canada La Physique au Canada

Transcription

Physics in Canada
La Physique au Canada
Vol. 52, No. 2
March/April 1996
mars/avril 1996
FEATURING:
The Physics of Dilute 2D Electron
and Hole Systems in Si-Based
Heterostructures
by M. D'lorio
Nouvelle source de plasma pour le
traitement des matériaux:
Magnétoplasma à onde de surface
by J. Margot
Evaluation of the Acid Deposition and
Oxidant Model with Ozone and
Sulphur Dioxide Data from High
Elevation Sites
by C. Banic et al
Contrôle des modes latéraux de
lasers à semi-conducteurs:
Expériences et simulations
by N. McCarthy et al
WOMEN PHYSICISTS IN CANADA
LES PHYSICIENNES AU CANADA
Symmetry-Violating NN
Potentials in the Nucleus
by A. C. Hayes
(nn)
2108.8
2212.5
Outflows from Spiral Galaxies
by J. A. Irwin
lll-V Semiconductor Characterization
for Optoelectronics
by C. Miner
and. in the PHYSICS AND
EDUCATION SECTION:
The Early History of Women in Univ.
Physics: A Toronto Case Study
by A. Prentice
2325.8
Using Nonsexist Language/Rendering
the CAP By-laws Gender Neutral
by R. King and D. Poirier
Women Physics Faculty in Canada
by J. Lagowski and J. McKenna
2437.5
2550.0
Women Students in Physics in
Canada: A Decade of Progress
by A. McMillan and E. Svensson
WES - Women in Eng. and Science:
A Canadian Success Story at NRC
by M. D'lorio
The Committee on the Status of
Women in Physics of the American
Physical Society
by L. Martinez-Miranda
Individual and Family Profiles
Canadian Publications Product Sales Agreement
No. 0484202/ Envois de publications
canadiennes numéro de convention 0484202
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OF P H Y S I C I S T S
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CANADIAN ASSOCIATION
OF P H Y S I C I S T S
ASSOCIATION CANADIENNE
DES P H Y S I C I E N S ET P H Y S I C I E N N E S
151 RUE SLATER STREET. SUITE 903. OTTAWA. ONTARIO CANADA K1P 5H3
TELEPHONE: (613) 237-3392 FAX: (613) 238-1677 E-MAIL CAP@physics.carleton.ca
NOUS
DEMENAGEONS !
Le 14 mai 1996, l'Association
canadienne des physiciens et
physiciennes occupera ses nouveaux locaux dont les coordonées sont les
suivantes:
ADRESSE POSTALE
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(ou en personne)
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HEURES D'OUVERTURE
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Au plaisir et à bientôt.
Vol. 52, No. 2
Physics in Canada
March/April 1996
mars/avril 1996
INDEX
FEATURE NON-TECHNICAL
ARTICLES:
Pages 50-52
Pages 94-96 (cont'd on pg. lOO)
The Early History of Women in University
Physics: A Toronto Case Study
by A. Prentice
Editorial and Calendar /Ca/e/idrier
Pages
53-57
Science
Policy Update / Mise à jour sur la politique
scientifique
Pages 97-100
Using Nonsexist Language/Rendering the
CAP By-Laws Gender Neutral /
L'utilisation
Pages 58-60
News / Nouvelles
University News / Échos des Universités
International News / Nouvelles
Internationales
d'un
Electron
l'ACP
modification
pour
le rendre
la
Pages 108-110 (cont'd on pg. 113)
Women Students in Physics in Canada: A
Decade of Progress
by A.C. McMillan and E. Svensson
and
Hole
Systems
in
Si-Based
Pages 111-112
WES - Women in Engineering and Science:
A Canadian Success Story at NRC I PIC -
Pages 69-71
Nouvelle Source de Plasma pour le traitement des matériaux: Magnétoplasma
à onde de surface
by J. Margot
Evaluation of the Acid Deposition and Oxidant Model with Ozone and Sulphur
Dioxide Data from High Elevation Sites
by C.M. Banic et al
Pages 77-80
Contrôle des modes latéraux de lasers à semi-conducteurs: Expériences et
simulations
by N. McCarthy et al
Programme
programme
d'ingènieures
canadien
et
couronné
chercheuses:
de
succès
CNRC
Page 113
The Committee on the Status of Women
in Physics of the APS
by L. Martinez-Miranda
Pages 114-126
Individual and Family Profiles by i. condrea;
N.R. Evan»; D. Pinsonneault; D. Poirier; M. Hilts,
C. Lucas, S. Ghosh and C. Klatt; M.A. White; A. Hayes
and S. Sterbenz; J. Berlinsky and C. Kallin;
J. and M. Thewalt; end Y. Qi
Page 102
Institutional Members I Membres
Sustaining Members / Membres
Pages 86-89
Outflows from Spiral Galaxies
by J.A. Irwin
Pages 103-105
The CAP 1 9 9 4 Income Survey
institutionels
de
soutien
Pages 127-129
Books Received / Livres reçus
Book Reviews / Revues des livres
Pages 90-93
lll-V Semiconductor Characterization for Optoelectronics
by C.J. Miner
Page 130
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Published - Jan/Feb., March/Apr., May/June, July/Aug., Sept/Oct.. Nov/Dec.
Un
au
by M. D'lorio
Symmetry-Violating NN Potentials in the Nucleus
by A.C. Hayes
Advertising Rates
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de
non-sexiste
Women Physics Faculty in Canada
by J.B. Lagowski and J. McKenna
Canadien(ne)s
FEATURE TECHNICAL ARTICLES:
2D
non-sexiste/La
de
by R. King and D. Poirier
Page 61
Canadian Physicists / Physiciens et Physiciennes
News from Corporate Members
The Physics of Dilute
Heterostructures
by M. D'lorio
langage
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FRONT COVER: Fig. 2. "lll-V Semiconductor
Characterization for Optoelectronics" by
C.J. Miner (pg. 90). (Top) The reflectance at a
wavelength of 1000 nm is displayed for an InP layer
grown on an In MGa 47As marker layer. (Bottom) With
the additional information inferred from at least one
reflectance spectrum for each fringe, the sRS map can
be translated to this thickness map.
EDITORIAL The Bulletin of
The Canadian Association
of Physicists
Bulletin de l'Association
canadienne des
physiciens et physiciennes
EDITORIAL BOARD /
COMITÉ DE RÉDACTION
Editor / Rédacteur en chef
J.S.C. McKee
Accelerator Centre
Physics Department
University of Manitoba
Winnipeg, Manitoba R3T 2N2
(204) 474-9874; fax: (204) 269-8489
e-mail: mckee@physics.umanitoba.ca
Associate Editor / Rédactrice associée
F .M. Ford
Managing / Administration
Book Review Editor / Rédacteur à la
critique des livres
A. Roberge
Dept. of Physics and Astronomy
Laurentian University
Sudbury, ON P3E 2C1
(704) 675-1151x2234
e-mail: andre@gollum.pbys.laurentian.ca
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P.O. Box 5000
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Fax: (902) 867-5153
e-mail: msteinit@juliet.stfx.ca
J.G. Cook
Institute for Microstructural Sciences
National Research Council (M-50),
Montreal Rd.,
Ottawa, Ontario Kl A 0R6
(613) 993-9407
Fax: (613) 957-8735
Béla Joos
University of Ottawa
Ottawa, Onl. K1N6N5
(613) 564-3460 Fax:(613) 564-6712
e-mail: bjosj@acadvm 1 uottawa.ca
Terry J. McKee
Lumonics inc.
105 Schneider Road
Kanata. Ont. K2H 8C3
(613) 592-1460
Fax: (613) 592-5706
R.H. Packwood
Metals technology laboratories
E-M-R
568 Booth St., Ottawa, Ont.
(613) 992-2288
lax: (613) 992-8735
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50
Physics in Canada
M arch/Aprill 9 9 6
It is an honour to be the first w o m a n invited to be the special editor of Physics in Canada,
in particular for a special issue on W o m e n Physicists. I made a presentalion at the CAP
Congress on the subject of " W o m e n in Physics - a M a t t e r of Education" in E d m o n t o n in
1 9 8 6 . Thus, it is especially interesting for me t o revisit the subject of w o m a n p h y s i c i s t s
after a decade and a particular delight t o present this special issue of Physics in Canada
celebrating their c o n t r i b u t i o n and presenting their v i e w of physics in Canada H o w e v e r , it is
w i t h s o m e trepidation that I w r i t e an editorial on this subject. Special editors t h a t have not
" s t u c k t o their k n i t t i n g " have not received particularly gentle t r e a t m e n t in Canadian physics
journals in the past.
" W o m a n p h y s i c i s t " . . . . s o m e feel that this expression is an o x y m o r o n . On the other hand,
many people, indeed many w o m e n , feel that barriers for w o m e n w h o w a n t a career as a
physicist have been e f f e c t i v e l y dealt w i t h t h r o u g h policies on m a t e r n i t y leave, w i d e r access
t o day care, universal medical benefits and the like. " S u f f r a g e t t e s " of yesteryear w h o
chained t h e m s e l v e s t o fences t o w i n the v o t e for w o m e n w o u l d undoubtedly be amazed t o
see the changes in t o d a y ' s w o r l d in w h i c h it is possible for w o m e n to integrate career and
f a m i l y life in a seamless w a y . Yet, the survey of university physics d e p a r t m e n t s reported on
in this issue indicates that only 1 3 % of Canadian PhD students in physics are w o m e n and
there remain major university physics d e p a r t m e n t s w h i c h have no female f a c u l t y m e m b e r s .
Indeed, there has been substantial cultural change in Canada w i t h respect t o the role and
position of w o m e n . " W o m e n in Canada, A Statistical Report" released by Statistics Canada
in A u g u s t , 1 9 9 5 , summarizes the status of w o m e n in Canada in the early ninetys. There is
good n e w s and not so good n e w s . There has been an increase in the participation of
w o m e n as university s t u d e n t s in general. In the 1 9 9 2 - 9 3 academic year, w o m e n a c c o u n t e d
for 5 2 % of all full t i m e university students. In some scientific disciplines representation of
w o m e n has increased dramatically. In 1 9 9 4 , w o m e n made up 3 2 % of all d o c t o r s and
d e n t i s t s , up f r o m 1 8 % in 1 9 8 2 . A n education pays. W h i l e at all levels of educational
a t t a i n m e n t w o m e n ' s earnings remain l o w e r t h a n those of men, female u n i v e r s i t y graduates
e m p l o y e d f u l l - t i m e , earned 7 5 % as m u c h as their male colleagues in 1 9 9 3 , w h i l e the
average pre-tax income of all w o m e n aged 15 and over w a s only 5 8 % of the average
i n c o m e of men. The e m p l o y m e n t rate of w o m e n increases dramatically w i t h educational
a t t a i n m e n t . In 1 9 9 4 , 7 7 % of female university graduates as c o m p a r e d w i t h 8 2 % of male
graduates w e r e employed.
There is also some not so good n e w s for w o m e n . This same report says that in 1 9 8 2 , 1 5 %
of professionals e m p l o y e d in the natural sciences, engineering and m a t h e m a t i c s w e r e w o m e n
and in 1 9 9 4 this has risen t o only 1 9 % . T h o u g h w o m e n do make up more than half of full
t i m e u n i v e r s i t y students, in 1 9 9 2 - 9 3 w o m e n made up just 3 5 % of those w o r k i n g full t i m e
t o w a r d their d o c t o r a t e s . In 1 9 9 4 , 7 0 % of all e m p l o y e d w o m e n w o r k e d in teaching, nursing
and related health occupations, clerical positions, or sales and service o c c u p a t i o n s c o m p a r e d
to 3 1 % of men. Thus, many w o m e n continue t o pursue career paths that are traditional t o
t h e m , and physics is not one of these. It is interesting to reflect on these s t a t i s t i c s in the
c o n t e x t of A l i s o n Prentice's article on w o m e n in physics decades ago in Canada.
These d r y statistics s h o w that w h i l e advances have been made over recent decades, for
w h a t e v e r reason, there are career differences b e t w e e n w o m e n and men w h i c h persist in our
culture. Reasons are t o o many t o explore here and the discussion could b e c o m e long, and
riddled w i t h non scientific opinion and debate. The f a c t s speak for t h e m s e l v e s .
The objective of this issue is t o present an o v e r v i e w of w o m a n physicists in Canada as w e
approach the end of the millenium. A s you w i l l see, w e have m u c h to celebrate in the
c o n t r i b u t i o n s of w o m e n t o physics in Canada. A s you w i l l also see, these c o n t r i b u t i o n s go
far beyond the intellectual...the presence of these w o m e n is beginning t o s t r e n g t h e n the
fabric of our profession and to s t r e t c h it, as some of the profiles of s t u d e n t , married couples
and n e w c o m e r s t o Canada illustrate.
The Canadian A s s o c i a t i o n of Physicists has supported a C o m m i t t e e t o Encourage W o m e n in
Physics (CEWIP) since 1 9 8 3 . Interestingly enough, the c o m m i t t e e w a s initiated by m e n and
has been supported by t h e m throughout its history. The " t w o J i m ' s " as they have c o m e t o
be a f f e c t i o n a t e l y k n o w n are J i m Prentice and J i m M e g a w . Both n o w retired, these t w o
acted as mentors and examples for many w o m e n w h o participated in the c o m m i t t e e over
the past decade.
Remarkably, it has been men w h o like w o m e n and respect their
c o n t r i b u t i o n t o the c o m m u n i t y w h o have made the c o m m i t t e e w o r k a b l e . In the early years,
M o n a J e n t o , then Secretary of the CAP and herself a science graduate and pioneer, w a s an
a c t i v e supporter and participant. A major problem has been g e t t i n g w o m e n t o become
involved w i t h the c o m m i t t e e and t o take on w o r k associated w i t h it. The c o m m o n thread is
that w o m e n have too m u c h t o do.
The current chair of the c o m m i t t e e is Debbie Poirier, w h o s e profile is featured in this issue.
Please provide c o m m e n t s and advice on the d i r e c t i o n of the c o m m i t t e e t o her. Her e-mail
address is
The CEWIP has been a truly national c o m m i t t e e w i t h corresponding m e m b e r s h i p of about 2 0
people f r o m coast t o coast. Each individual member of CEWIP undertakes their o w n slate of
activities w h i c h t y p i c a l l y include career talks, collection of information
on some aspects of
the issue, or liaison w i t h other organizations interested in w o m e n in science. For,
example J i m M e g a w undertook a survey of all the universities in the w o r l d t o obtain data
about the p a r t i c i p a t i o n rates of w o m e n in
physics
and
reported
on
"Gender
D i s c r i m i n a t i o n in the W o r l d ' s Physics
D e p a r t m e n t s " at the Gender and Science
and Technology m e e t i n g in Australia in
1 9 9 1 . The c o m m i t t e e has u n d e r t a k e n
some additional specific a c t i o n s :
-
Until 1 9 8 7 there had rarely been a
w o m a n on the CAP Lecture Tour. In
order to change this s i t u a t i o n , names of
o u t s t a n d i n g w o m a n speakers
were
included ( w i t h the Education D i v i s i o n ' s
permission) on the C A P list for several
years. Inevitably the w o m e n received
more speaking i n v i t a t i o n s on average
than the men. M a r y A n n e W h i t e , w h o s e
profile appears herein, w a s one of the
first and m o s t popular. Lately, the
departments
have been
nominating
w o m a n speakers d i r e c t l y .
A D i r e c t o r y of W o m e n in Physics in
Canada has been developed. This
d i r e c t o r y is n o w w i t h the CAP o f f i c e
for use by potential e m p l o y e r s , seekers
of graduate s t u d e n t s . The c o m m i t t e e is
looking for s o m e o n e to take on the
continued responsibility of updating the
list and ensuring its availability.
M e e t i n g s are held several t i m e s a year,
a l w a y s at the CAP Congress
in
whichever
city
it
occurs
and,
additionally, in Quebec or Ontario.
There w a s a w o m e n ' s session at C A M
95 in Quebec C i t y w h i c h included
M e x i c a n and A m e r i c a n p h y s i c i s t s .
The Canadian c o m m i t t e e has c h o s e n a l o w
keyed approach to the e q u i t y issue and tries
to w e a v e a thread of consciousness about
the issue into the business of the CAP. The
APS has t a k e n a more high profiled
approach and some of their excellent
p r o g r a m s are described in this issue.
This issue takes the Canadian
approach.
W e have no strident d e m a n d s t o present.
We
do
have
an o v e r v i e w
of
the
t r e m e n d o u s present and potential f u t u r e
c o n t r i b u t i o n of w o m e n to physics in
Canada. W e have a collage of technical
w r i t i n g s over a broad selection of fields,
s o m e nontechnical papers on a v a r i e t y of
t o p i c s related t o w o m e n , and some profiles
of w o m a n physicists and physics couples
w h o say in their o w n w a y w h a t p h y s i c s is
all about in Canada t o d a y . These profiles
capture the e n t h u s i a s m and c r e a t i v i t y of
w o m a n p h y s i c i s t s and a l t h o u g h none of
t h e m highlight major issues w i t h i n the
community,
some
common
themes
emerge.
The one t h a t emerges m o s t
clearly has little t o do w i t h overt barriers or
discrimination.
It is the d i f f i c u l t y of
m a n a g i n g dual careers in p h y s i c s .
In
t o d a y ' s t o u g h e c o n o m i c c l i m a t e it is
d i f f i c u l t to manage one science career. It
is not surprising that it is v a s t l y more
d i f f i c u l t to manage t w o . N u m b e r s are part
of the issue here. M o s t w o m e n in p h y s i c s ,
according t o the APS, if they m a r r y , marry
m e n in science (see A n n a H a y e s ' and
Steve Sterbenz' profile for numbers). The
w o m e n are t y p i c a l l y s o m e w h a t younger
than the m e n and hence not as far along in
their careers w h e n t h e y enter the marriage.
T h u s , w h e n a f a m i l y is desired, it is likely
to make excellent sense for the w o m a n to
give
up
or
postpone
her
career.
U n f o r t u n a t e l y , m a n y of these
highly
c o m p e t e n t and enthusiastic w o m e n never
r e t u r n to the field.
On t o p of all the
d o m e s t i c issues t h e y m u s t deal w i t h , there
are a host of rules against n e p o t i s m , etc,
that can limit a w o m a n ' s o p p o r t u n i t y t o
find suitable e m p l o y m e n t in the same
geographical area as her husband.
This
issue arises again and again in the
s t a t e m e n t s provided by w o m e n in this
issue. Solutions range f r o m long range
c o m m u t i n g t o challenging the s y s t e m .
U n f o r t u n a t e l y , w h a t e v e r the solution it is
likely to have ongoing i m p a c t s on the
w o m a n ' s happiness and her career, not t o
m e n t i o n her f a m i l y . It is clear that one
piece of advice that should be passed on
to w o m e n s t u d e n t s is to ensure that the
m a n she marries is s u p p o r t i v e of her
m a i n t a i n i n g a career. That support can be
crucial to ensuring increasing participation
of w o m e n in the physics c o m m u n i t y .
Understanding the issue can help the
physics c o m m u n i t y deal w i t h such couples
in a more humane w a y .
ERRATUM
In the "Ph.D. Degrees A w a r d e d at
Canadian
Universities
s e c t i o n
of
in
1995"
the
1 9 9 6
January/February issue of Physics
Canada
A b d u l Elezzabi
in
was
inadvertently listed as currently at a
Post
Doctorate
Fellowship
University of Edmonton.
at
the
This entry
should have read the University of
Alberta. Our apologies to all current
and former graduates/employees of
the University
of Alberta for
this
error.
Please read on and enjoy.
W e are
interested in y o u r response to this issue.
Dr. A n n C. McMillan
Guest Editor
Additional Reading Suggested by our Readers:
A Passion for Physics - The S t o r y of a
W o m a n Physicist
J o a n Freeman
IOP Publishing, Bristol, England 1 9 9 1
scientists? Other than M a d a m e Curie, I
c a n ' t think of a n y , " w h i c h expressed an
attitude
that
was
even more
prevalent
before this book w a s published.
Carol Herzenberg
A n o t h e r source of i n f o r m a t i o n is an
international
reference
listing
and
biographical d i r e c t o r y of some notable
w o m e n scientists f r o m ancient t o m o d e r n
t i m e s . " W o m e n Scientist f r o m A n t i q u i t y
to the Present: A n I n d e x " w a s published
by Locust Hill Press, W e s t C o r n w a l l CT in
1 9 8 6 , and is available f r o m the publisher
and is in most major u n i v e r s i t y libraries. It
includes w o m e n in m a t h e m a t i c s , medicine,
and engineering; there are over 2 5 0 0
individual entries that w i l l help y o u locate
further biographical i n f o r m a t i o n on all of
these w o m e n .
You m a y find this book
useful - it w a s developed in part to
respond t o such s t a t e m e n t s as " W o m e n
W o m e n Scientists in America: Before
Affirmative Action 1940-1972. By Margaret
W. Rossiter, John Hopkins University Press:
1995.
D. Poirier
INRS
mars à avril 1 9 9 6
51
CALENDAR / CALENDRIER
information,
please
contact:
A. Donszelmann at Tel: + 3 1 (20I
5256334, Fax: + 3 1 (20) 525 5102,
e-mail: zicap@phys.uva.ni. 11-23
1996 JUNE TO 1997 JUNE
Combinations and Group Theory
The
Centre
de
recherches
mathématiques is hosting a year long
program in combinatorics and group
theory in 1996-97. The year will be
organized around a certain number of
workshops spread throughout the year.
For a schedule of events, please
contact: Louis Pelletier,CRM, Université
de Montréal, CP 6128, Succ. CentreVille, Montréal, QC, H3C 3J7 or e-mail
to: ACTIVITES@CRM.UMontreal.CA;
WWW http://www.CRM.UMontreal.CA
1996 JUNE
7-11
9-12
European Research Conference on
Fundamental Aspects of
Surface
Science: Semiconductor Surfaces, C.
Sebenne
(Paris)
Blankenberge,
Belgium. More information can be
obtained on the World Wide Web server
at: http:Wwww.esf.org
CNA/CNS Annual Conference, New
Brunswick.
For more information,
please contact: Ms. Tatiana Wigley,
CNA/CNS Office, Toronto Ontario. Tel:
(416)977-6152; Fax: (416)979-8356.
16-19 CAP Annual Congress, University of
Ottawa, Ottawa, Ontario. For Congress
Information see 1996 January /February
Physics in Canada or Congress section
of Univ. of Ottawa home page at
http://www.physics.uottawa.ca/
1996 SUMMER
Physics in
Industry
International
Conference, Nyzhny Novgorod, Russia.
For more information, please contact:
Professor S.P. Kapitza,
Euro-Asian
Physical
Society
President,
17
Kursovoy, Moscow 119034, Russia.
Fax:
(095)
943-76-77;
E-mail:
marina@ eaps.msk.ru.
1996 JULY
8-10
Third International Workshop on Laser
Beam and Optics Characterization / 3"
Atelier international sur la caractérisation des faisceaux et de l'optique laser,
Québec, QC. Pour plus d'information,
veuillez contacter Michel Morin, Institut
national d'optique, 369, rue Franquet,
Sainte-Foy, QC, Canada, G1 P 4N8, Tel:
(4181 657-7006, Fax: (418) 657-7009;
cour.élec: morin@ino.qc.ca.
1996 AUGUST
5-9
Zeeman-Effect Centenary/ International
Conference on Atomic Physics XV
(ZICAP), Van der
Waals Zeeman
Laboratory, University of Amsterdam,
Valckenierstraat
65,
1018
XE
Amsterdam, The Netherlands. For more
11-23 CRM Summer School/Combinatories
and Group Theory, Banff, Alberta. For
more
information
contact:
CRM
Summer School, CRM, Université de
Montréal, CP 6128, Succ. Centre-ville,
Montréal, QC, H3C 3J7, e-mail:
ACTIVITES@CRM.UMontreal.CA, Fax.
(514) 343-2254, Tel: (514) 343-2197
17-24 8th International Organization of
Science and Technology Education
(I0STE)
Symposium,
Edmonton,
Alberta. For more information, please
contact:
Continuing
Professional
Education:
Faculty
of
Education,
University of Alberta, 4-116 Education
North, Edmonton, Alberta, T6G 2G5,
Tel: (403) 492-0394, Fax: (403) 492
0390.
19-23 17th
General
Congress
of
the
International Commission for Optics,
Taejon, Korea. Theme: "Optics for
Science and New Technology". For
more information, please contact: ICO17C96) Secretariat, Prof. B.Y. Kim,
Department
of
Physics,
KAIST,
373-1 Kusong-dong,Yusong-gu,Taejon
305-701, Korea. Tel: + 82-42-8692527; Fax: +82-42-869-5527.
27-30 2nd
International
Conference
on
hyperons, charm and beauty baryons,
Concordia
University,
Montreal,
Quebec. For more information, please
contact: Lynn Chapman-Baker, Physics
Dept., Concordia University, Montreal,
QCH3G1 M8;Beauty@vax2.Concordia,
ca
1996 SEPTEMBER
Aug.31- European Research Conference on
Sept. 5 Advanced Quantum Field Theory:
Integrability, Conformai Invariance,
Topological
Field
theory
and
Applications, V. Rittenberg (Bonn) - La
Londe-les-Maures,
France.
More
information can be obtained on the
World
Wide
Web
server
at:
http:Wwww.esf.org
9-13
EPS 10 Trends in Physics, 10th General
Conference of the European Physical
Society, Sevilla, Spain.
For more
information, please contact: Organizing
Secretariat, Proconsur, Avda. San
Francisco Javier n° 15, 4", E-41018
Sevilla (Spain) Tel: (34-5) 492 27 55
16-19 Deep Geologic Disposal of Radioactive
Waste, Winnipeg, Manitoba. For more
information,
please
contact:
Mr. C. Vandergraaf, AECL Research -
WL, Pinawa, Manitoba, ROE 1L0. Tel:
(204) 753-2311 ext 2592.22-26
21-26 European Research Conference on
Quantum Optics, K. Burnett (Oxford) Castelvecchio Pascoli, Italy. More
information can be obtained on the
World
Wide
Web
server
at:
http:Wwww esf org
22-26 Physics and Industry (PHYSIN-96),
Nyzhny Novgorod (Russia). For more
information please contact: Euro-Asian
Physical Society, 17, Kursovoj bystr.,
Moscow, 119034, Russia. Tel: (095)
943-7677; Fax: (095) 943-7686,
e-mail: marina@eaps.msk.ru.
24-26 BEM 18: 18th International Conference
on Boundary Element Methods, Braga,
Portugal.
Abstract
deadline
December 18, 1995. Final paper due
April 2 9 , 1 9 9 5 . Sponsors: International
Society for Boundary Elements, for
more information contact Liz Kerr,
Wessex
Institute of
Technology,
Ashurst Lodge, Ashurst, Southampton
S040 7AA,
UK. Tel:
(44)(1703)
293223, Fax: (44)11703) 292853,
E-mail: cmi@ib.rl.ac.uk.
1996 SEPTEMBER
Sept. 28
Oct. 3 European Research Conference on
Chaotic Phenomena in Nuclear Physics
S. Aberg (Lund) - Aghia Pelagia, Crete,
Greece. More information can be
obtained on the World Wide Web server
at: http:Wwww.esf.org
1997 JULY
1-7
Joint
Scientific
Assemblies:
International
Association
of
Meteorology and Atmospheric Sciences
/ International Association for the
Physical Sciences of the Oceans,
Melbourne, Australia.
For more
information,
please
contact:
IAMAS/IAPSO Secretariat, Convention
Network, 224 Rouse Street, Port
Melbourne Victoria 3207 Australia. Tel:
+ 61 3 9646 4122; Fax: + 6 1 3 9646
7737; e-mail: mscarlett@peg.apc.org.
25th
International
Cosmic
Ray
Conference, Durban, South Africa. For
more information contact: National
Organizing Committee 25th ICRC,
Space Research Unit, Department of
Physics, Potchefstroom University for
Che, Potchefstroom 2520, South
Africa.
Tel: + 2 7 - 1 4 8 - 2 9 9 2 4 2 3 ,
Fax: + 2 7 - 1 4 8 - 2 9 9 2 4 2 1 ,
E-mail:
ICRC97@PHYSICS.PUK AC.ZA
MARK YOUR CALENDARS
- FUTURE CAP CONFERENCES -CAP 1997 Annual Congress, 1997 June 8-11, University of Calgary.
CAP 1998 Annual Congress, 1998 June 14-17, University of Waterloo.
A n y universities interested in hosting a CAP Annual Congress can send a letter of interest t o the CAP
Office, Bur./Suite 112, Imm. McDonald Bldg., 150 Louis Pasteur, Ottawa, ON K I N 6N5. The letter should include an
indication of what year you are interested in, keeping in mind that the Congress travels Central-East-Central-West.
52
Physics in Canada
M arch/Aprill 9 9 6
SCIENCE POLICY UPDA TE / MISE À JOUR SUR LA POLITIQUE SCIENTIFIQUE
A t t h e s t a r t of his t e r m as C A P
P r e s i d e n t , P.S. V i n c e t t s t a t e d t h a t t h e
m o s t i m p o r t a n t t a s k f o r his P r e s i d e n c y
w o u l d be ( w i t h t h e help of m a n y o t h e r s )
t o e s t a b l i s h C A P as a t r u l y e f f e c t i v e
voice for science, one w h i c h w o u l d
speak t o g o v e r n m e n t s
clearly
and
e f f e c t i v e l y o n behalf of p h y s i c s a n d of
s c i e n c e as a w h o l e . A f t e r a n e n o r m o u s
a m o u n t of e f f o r t , it a p p e a r s t h a t t h i s is
b e c o m i n g a f a c t ; t h e r e are m a n y in
O t t a w a w h o w o u l d n o w tell y o u t h a t
t h e C A P is o n e of a h a n d f u l of l e a d i n g
v o i c e s f o r s c i e n c e b o t h n a t i o n a l l y a n d in
m a n y p r o v i n c e s . N o w t h a t t h e C A P has
t h e r e s o u r c e s a n d e x p e r t i s e in p l a c e ,
P.S. V i n c e t t b e l i e v e s t h a t t h e C A P c a n
play a c r i t i c a l l y i m p o r t a n t role in t h e
challenges w h i c h continue t o
face
physicists,
whether
they
be in a
u n i v e r s i t y s e t t i n g or e l s e w h e r e .
The
C A P m u s t s p e a k f o r p h y s i c s as a
whole.
T h e s e are:
1.
T h a t a n y s c i e n c e p o l i c y h a v e as a
g o a l t h e c r e a t i o n of a s u s t a i n a b l e
d i s t r i b u t i o n of e f f o r t b e t w e e n basic
science,
applied
science,
development and commercialization
of t h e d e v e l o p m e n t s .
2.
A
major
impediment
to
the
commercialization
of
Canadian
r e s e a r c h a n d d e v e l o p m e n t is t h e
reluctance
of
our
financial
institutions to provide financing for
l a t e - s t a g e d e v e l o p m e n t a n d initial
p r o d u c a t i o n of n e w p r o d u c t s of
small and m e d i u m sized enterprises.
W h i l e t h e g o v e r n m e n t has r e c e n t l y
announced several programs
to
a d d r e s s t h i s p r o b l e m , it s h o u l d be
r e c o g n i z e d as a n o n - g o i n g c h a l l e n g e
requiring additional responses.
Productive Meetings w i t h Government
A report o n s c i e n c e p o l i c y a c t i v i t i e s
undertaken
recently
follows.
C o m m e n t s a n d s u g g e s t i o n s are i n v i t e d
f r o m C A P m e m b e r s . Please d i r e c t t h e m
t o F . M . Ford, S c i e n c e Policy O f f i c e r ,
C a n a d i a n A s s o c i a t i o n of
Physicists,
Suite
112,
McDonald
Building,
1 5 0 Louis
Pasteur
Ave.,
Ottawa,
Ontario,
K1 N
6N5;
email
CAP@physics.uottawa.ca.
LOBBYING
National Consortium
T h e C A P w r o t e m o s t of t h e b r i e f i n g
paper o n t h e I m p o r t a n c e of R e s e a r c h
which the
National Consortium
of
Scientific and Educational
Societies
u s e d in t h e i r m e e t i n g s w i t h a large
n u m b e r of M i n i s t e r s a n d s e n i o r c i v i l
s e r v a n t s in N o v e m b e r / D e c e m b e r 1 9 9 5 .
T h i s paper f o c u s e d o n t h e i m p o r t a n c e
of t h e w h o l e s p e c t r u m of r e s e a r c h , a n d
particularly emphasized the importance
of l o n g - t e r m w o r k .
The Consortium recently asked
its
members
for
input
regarding
a
Consortium
science
policy.
D. M c D i a r m i d , D i r e c t o r of P r o f e s s i o n a l
Affairs,
felt,
in
consultation
with
P.S. V i n c e t t , t h a t f r o m t h e C A P ' s p o i n t
of v i e w t h e r e are t w o issues w h i c h w e
f e e l m u s t , a m o n g o t h e r s , be part of any
C o n s o r t i u m science policy d o c u m e n t .
This year t h e C A P joined w i t h the
C h e m i c a l S o c i e t y of C a n a d a (CSC) t o
c o n d u c t the first joint lobby e f f o r t . The
mid-February
meetings
with
J o n Gerrard,
Minister
of
State
for
Science, Research and D e v e l o p m e n t ,
and other government officials were
a t t e n d e d o n behalf of t h e C A P by
Paul V i n c e t t , P r e s i d e n t ; Bev R o b e r t s o n ,
Vice President;
Don
McDiarmid,
D i r e c t o r of P r o f e s s i o n a l A f f a i r s ; a n d
F r a n c i n e Ford, E x e c u t i v e D i r e c t o r . C S C
r e p r e s e n t a t i v e s i n c l u d e d President Ron
Steer; Vice-President
Vedene Smith,
and Executive Secretary Anne Alper.
Discussions w i t h Gerrard f o c u s e d on
t h e l o n g o v e r d u e report o n t h e f e d e r a l
Science and Technology Review, h o w
a d v i c e o n s c i e n c e a n d t e c h n o l o g y is
p r o v i d e d t o g o v e r n m e n t , t h e e f f e c t of
the cuts to the transfer payments on
university research and the need for
resources t o bring proven t e c h n o l o g y t o
the marketplace.
Gerrard
emphasized
the
need
for
independent advice on science and
t e c h n o l o g y issues.
He s a i d t h a t t h e
s c i e n c e l o b b y is d i v e r s e a n d not w e l l
versed
in
what
is
possible
in
government.
He u r g e d t h e s c i e n t i f i c
c o m m u n i t y t o t a k e the initiative and
create
a
structure
for
providing
c o h e r e n t , clear a d v i c e t o g o v e r n m e n t .
W i t h respect t o the need for resources
t o bring proven t e c h n o l o g y t o the
marketplace,
Gerrard
referred
to
p r o g r a m s s u c h as t h e n e w NRC-NSERC
Industry partnerships and the Western
Diversification Fund initiatives.
We
stressed the
fact
that
it
is
still
extremely difficult for small knowledgebased companies t o obtain funds for
new ventures.
The
effect
cuts
to
the
transfer
payments
will
have
on
research
i n f r a s t r u c t u r e at u n i v e r s i t i e s w a s also
raised.
G e r r a r d p o i n t e d out t h a t t h e
f e d e r a l g o v e r n m e n t does not get c r e d i t
f o r t h e f u n d s it i n v e s t s here.
G e r r a r d a d v i s e d us t h a t t h e report o n
t h e f e d e r a l S & T R e v i e w w a s t o be
released
with
the
budget.
His
Department will hold briefings on the
report
for
CAP,
CSC
and
other
organizations.
T h e e f f e c t s of t h e c u t s t o t h e t r a n s f e r
p a y m e n t s o n t h e r e s e a r c h c a p a b i l i t y of
u n i v e r s i t i e s w e r e also d i s c u s s e d w i t h
Peter A d a m s , M . P . , Chair of t h e C a u c u s
C o m m i t t e e on Higher Education. A d a m s
s a i d his C o m m i t t e e w a s f o r m e d t o
a d d r e s s higher e d u c a t i o n issues a n d
realizes t h e i m p a c t of t h e s e
cuts.
A d a m s s a i d t h a t t e a c h i n g is t h e m o r e
o b v i o u s p r o d u c t of u n i v e r s i t i e s a n d
r e s e a r c h is less v i s i b l e .
A l t h o u g h he
p o i n t e d o u t t h a t it w a s t h e n p r o b a b l y
t o o late t o i n f l u e n c e t h e u p c o m i n g
b u d g e t , he did feel t h a t
immediate
action may influence future strategy.
O n his a d v i c e , t h e C A P a n d t h e C S C
P r e s i d e n t s w r o t e t o t h e Prime M i n i s t e r
u r g i n g t h a t he g i v e s o m e i n d i c a t i o n in
the Speech f r o m the Throne on h o w
t h i s w i l l be a d d r e s s e d in t h e longer
term. The CAP's letter w a s distributed
t o C A P m e m b e r s by e m a i l o n 1 9 9 6
February 2 0 .
Subsequently a signific a n t n u m b e r of C A P m e m b e r s w r o t e
similar l e t t e r s t o t h e Prime M i n i s t e r
expressing their concern
over
the
current s i t u a t i o n and urging a national
s o l u t i o n in t h e longer t e r m . A d a m s also
u r g e d our o r g a n i z a t i o n s t o b r i n g t h e
message about the importance/exist e n c e of u n i v e r s i t y r e s e a r c h t o t h e M P s
in t h e i r local ridings. In a later m e e t i n g ,
Adams stated that the follow-up to
t h e s e m e e t i n g s by t h e p h y s i c i s t s a n d
t h e c h e m i s t s has b e e n v e r y i m p r e s s i v e .
The need for science and t e c h n o l o g y t o
h a v e a higher p r i o r i t y o n t h e g o v e r n m e n t ' s a g e n d a w a s raised in all our
m e e t i n g s . A r t h u r C a r t y , FCIC, President
53
of t h e N a t i o n a l R e s e a r c h C o u n c i l , s a i d
t h a t t h i s w i l l not h a p p e n u n t i l p e o p l e are
c o n v i n c e d of t h e v a l u e of S & T . He sees
a n i m p o r t a n t role f o r s c i e n t i f i c s o c i e t i e s
in b u i l d i n g s c i e n c e a w a r e n e s s w i t h t h e
public. W i t h o u t this, f u t u r e cuts t o S & T
b u d g e t s are i n e v i t a b l e .
Carty
said
that
the
government
p r i o r i t i e s are j o b s a n d g r o w t h . W e m u s t
work
with
industry
to
convince
g o v e r n m e n t of t h e role of s c i e n c e in
this process.
He s a i d t h a t a r e c e n t
s t u d y has s h o w n t h a t t h e I R A P P r o g r a m
created 9 , 0 0 0 n e w jobs and saved
6 , 0 0 0 e x i s t i n g j o b s . F u n d i n g f o r IRAP
s u n s e t s in 1 9 9 8 - 9 9 a n d he w o u l d like
o u r a s s i s t a n c e in p u b l i c i z i n g t h e v a l u e
of t h e p r o g r a m .
T h e E c o n o m i c Policy S e c r e t a r i a t in t h e
D e p a r t m e n t of F i n a n c e p r o v i d e s a d v i c e
to
the
Minister
of
Finance
on
macroeconomic
policy and
program
design
and
development
including
a d v i c e o n p r o p o s a l s b r o u g h t f o r w a r d by
o t h e r M i n i s t e r s . Peter C a m e r o n , G r o u p
Chief, Industry, Regional and Corporate
P o l i c y in t h i s D e p a r t m e n t , s a i d t h e r e is
a large s c i e n c e a n d t e c h n o l o g y e f f o r t
c u r r e n t l y in g o v e r n m e n t d e p a r t m e n t s
w h i c h , w i t h t h e t h r u s t of t h e p r e s e n t
g o v e r n m e n t , he s e e s as m o v i n g t o t h e
p r i v a t e s e c t o r . T h e c u r r e n t l o w level of
R & D d o n e by i n d u s t r y , d e s p i t e t h e
relatively
low
cost
of
conducting
research
in
Canada,
was
raised.
Government procurement and w o r l d
p r o d u c t m a n d a t e s w e r e e x p l o r e d as
possible mechanisms for improving t h e
situation.
T h e p o s i t i v e b e n e f i t s of b r i n g i n g n e w technology t o the marketplace and t h e
n e e d f o r s t a r t up f u n d s f o r
new
k n o w l e d g e b a s e d c o m p a n i e s w e r e also
discussed.
T h e g o v e r n m e n t is d o i n g
things t o make v e n t u r e capital available
b u t d o e s n ' t i d e n t i f y w h e r e it s h o u l d be
applied. Cameron said that t h e quality
of g r a d u a t e s a n d t h e r e s e a r c h c o m i n g
out
of
Canadian
universities
is
r e c o g n i z e d i n t e r n a t i o n a l l y as e x t r e m e l y
h i g h . T h e n e e d f o r p r o g r a m s t o build
on this research w a s identified.
The Science Promotion and Academic
A f f a i r s B r a n c h of I n d u s t r y C a n a d a is
responsible for policy on university
r e s e a r c h , s c i e n c e e d u c a t i o n a n d public
a w a r e n e s s . D o u g Hull, D i r e c t o r G e n e r a l
of t h i s
Department, said
strategic
t h i n k i n g in t h e s c i e n c e p o l i c y area has
d e c l i n e d in g o v e r n m e n t in r e c e n t y e a r s .
He s a i d t h a t he is w o r k i n g t o b r i n g m o r e
people w i t h scientific backgrounds into
his D e p a r t m e n t . H e also s t r e s s e d t h e
54
Physics in Canada
M arch/Aprill 9 9 6
need for t h e science c o m m u n i t y t o
develop a mechanism for giving advice
to government.
M a r t h a Piper, U n i v e r s i t y of A l b e r t a ,
Vice-President
(Research
and
External Affairs)
Hull e x p r e s s e d c o n c e r n a b o u t t h e f u t u r e
v i a b i l i t y of t h e C a n a d i a n u n i v e r s i t y
s y s t e m a n d t h e a b i l i t y of u n i v e r s i t i e s t o
cope w i t h current cutbacks and address
n e w c h a l l e n g e s , s u c h as e d u c a t i o n
supplied t o Canadians f r o m abroad
using computer n e t w o r k s .
Elizabeth
Cannon,
University
of
C a l g a r y , D e p a r t m e n t of G e o m a t i c s
Engineering
Ron S t e e r , U n i v e r s i t y of S a s k a t c h e w a n ,
D e p a r t m e n t of C h e m i s t r y
Bev
L o b b y i n g Can H a v e Results - U n i v e r s i t y
Advisory Committee
U s u a l l y o n e e x p e c t s l o b b y i n g t o be a
long-term
process
with
little
of
i m m e d i a t e i n t e r e s t t o r e p o r t . T h i s does
not a p p e a r t o be t h e c a s e f o r t h e
C A P / C S C l o b b y e f f o r t in m i d - F e b r u a r y .
F o l l o w i n g t h e m e e t i n g w i t h D o u g Hull
a n d s o m e of his s t a f f at I n d u s t r y
Canada,
Bev R o b e r t s o n ,
CAP
VicePresident,
received
a
call
from
Sue M i l n e of t h e U n i v e r s i t y Liaison
S e c t i o n of I n d u s t r y C a n a d a in early
March. The discussions w i t h CAP/CSC
t r i g g e r e d t h e e s t a b l i s h m e n t by I n d u s t r y
C a n a d a of a c o n s u l t a t i v e g r o u p of
u n i v e r s i t y people.
T h e U n i v e r s i t y A d v i s o r y Board w i l l be
p r o v i d i n g a d v i c e t o D o u g Hull, D i r e c t o r
General,
Science
Promotion
and
Academic Affairs and through him t o
Industry Canada. The recently-released
strategy
document.
Science
and
Technology
for
the
New
Century
(http://canada.gc.ca/depts/science/mai
n_e.html), emphasizes the importance
of a n a t i o n a l i n n o v a t i o n s y s t e m w i t h
s t r o n g linkages b e t w e e n j o b c r e a t i o n ,
e c o n o m i c g r o w t h , q u a l i t y of life a n d
a d v a n c e m e n t of k n o w l e d g e - a n d n o t e s
t h e need f o r e f f e c t i v e p a r t n e r s h i p s t o
provide t h e federal government w i t h
expert advice. This University A d v i s o r y
Board s h o u l d be in a n e x c e l l e n t p o s i t i o n
t o respond t o this interesting challenge
and opportunity.
Initial t o p i c s f o r d i s c u s s i o n by t h e
U n i v e r s i t y A d v i s o r y Board i n c l u d e t h e
commercialization
of
university
research;
distance
education;
international
marketing
of
postsecondary institutions; S&T indicators;
and research infrastructure.
M e m b e r s of t h e U n i v e r s i t y A d v i s o r y
Board ( f r o m W e s t e r n C a n a d a t o E a s t e r n
Canada) i n c l u d e :
Brett
Finlay,
University
of
British
Columbia,
Department
of
Microbiology and I m m u n o l o g y
Robertson, University
D e p a r t m e n t of P h y s i c s
of
Regina,
Katherine
Schultz,
University
of
Winnipeg, Associate Vice-President
(Research a n d G r a d u a t e S t u d i e s )
H e a t h e r M u n r o e - B l u m , U n i v e r s i t y of
Toronto, Vice-President (Research
a n d I n t e r n a t i o n a l Relations)
Bruce H u t c h i n s o n , Q u e e n ' s U n i v e r s i t y ,
D i r e c t o r of R e s e a r c h S e r v i c e s
Roger
Lecomte,
University
of
S h e r b r o o k e , D e p a r t m e n t of N u c l e a r
Medicine and Radiobiology
Gilles
Delisle,
INRS
cations, Directeur
recherche
Kelvin
Ogilvie,
President
Telecommunide c e n t r e de
Acadia
University,
J a a p T u i m a n , M e m o r i a l U n i v e r s i t y of
Newfoundland,
Vice-President
(Academic)
PARTNERSHIP A C T I O N GROUP O N
SCIENCE A N D ENGINEERING (PAGSE)
A s part of t h e CAP'S t h r u s t t o i m p r o v e
interactions
among
science-based
organizations,
P.S.
Vincett
(CAP
P r e s i d e n t ) , B.E. R o b e r t s o n ( C A P V i c e P r e s i d e n t ) , D. M c D i a r m i d ( D i r e c t o r of
P r o f e s s i o n a l A f f a i r s ) , a n d F . M . Ford
(Executive Director) met w i t h Michael
D e n s e of t h e R o y a l S o c i e t y of C a n a d a .
T h e m e e t i n g f o c u s s e d o n t h e s t a t e of
support for science w i t h i n government
(and t h e public in general). A l l parties
agreed t h a t a b r o a d b a s e d s c i e n c e
lobbying activity w a s becoming critical
if t h e c o m m u n i t y w a s t o h a v e any
i n f l u e n c e o n s c i e n c e p o l i c y in t h e
f u t u r e . Dr. D e n s e raised t h e p o s s i b i l i t y
of t h e Royal S o c i e t y t a k i n g a l e a d e r s h i p
role in t h i s a c t i v i t y , w h i c h w a s s t r o n g l y
s u p p o r t e d by t h e C A P r e p r e s e n t a t i v e s
p r o v i d e d a clear m a n d a t e a n d t e r m s of
reference
were
presented
to
the
p o t e n t i a l p a r t i c i p a n t s at t h e o u t s e t .
Several meeting have n o w t a k e n place.
at w h i c h t h e C A P has b e e n r e p r e s e n t e d
by D. M c D i a r m i d a n d B. C y c a ( C A P
Councillor-at-large).
A l t h o u g h t h e r e is
still a q u e s t i o n as t o w h e t h e r t h i s g r o u p
w i l l , in f a c t , f o r m t h e n a t i o n a l s c i e n c e
lobby organization, one activity that
was
recently
undertaken
was
the
d e v e l o p m e n t of a j o i n t r e s p o n s e o n t h e
S&T
Review
report
"Science
and
Technology for the N e w Century, A
Federal S t r a t e g y " .
The CAP provided
considerable input t o this response, a
c o p y of w h i c h f o l l o w s t h i s r e p o r t .
This r e s p o n s e w a s c a r e f u l l y d r a f t e d
w i t h t h e p u r p o s e t h a t it o p e n s o m e
doors for further PAGSE input t o the
g o v e r n m e n t a n d its b u r e a u c r a c y .
P R O V I N C I A L ENGINEERING A C T S
T h e e f f o r t s s u m m a r i z e d in t h e O c t o b e r D e c e m b e r 1 9 9 5 i s s u e of P h y s i c s in
Canada continue and have experienced
s u c c e s s in N o v a S c o t i a . T h e f o l l o w i n g
is a r e s u m e of t h e m o r e s i g n i f i c a n t
current activity.
N O V A SCOTIA: The n e w Nova Scotia
E n g i n e e r i n g A c t is p r o c e e d i n g t h r o u g h
t h e l e g i s l a t u r e . A P E N S has d o n e w h a t
t h e y s a i d t h e y w o u l d d o , s o w e are
c l o s e t o our h a v i n g f i r s t f u l l p r o v i n c e
using the e x e m p t i o n clause.
M A N I T O B A : The proposed revisions t o
t h e M a n i t o b a A c t d o not c o n t a i n a n
exemption clause and the proposed
d e f i n i t i o n of e n g i n e e r i n g p r a c t i c e leaves
m u c h t o be d e s i r e d . In a d d i t i o n t o t h e
proposed
revisions,
the
Manitoba
A s s o c i a t i o n has also d i s t r i b u t e d t o its
m e m b e r s h i p t h e CCPE d e f i n i t i o n of
engineering
practice,
including
the
CCPE/NSSC
exemption
clause,
for
feedback.
Several
CAP
officials,
i n c l u d i n g P.S. V i n c e t t , h a v e w r i t t e n t h e
Manitoba A s s o c i a t i o n urging t h e m t o
adopt
the
exemption
clause.
Discussions
with
the
Association
c o n t i n u e w i t h t h e v e r y s i g n i f i c a n t help
of R.C. Barber.
S A S K A T C H E W A N : T h e G o v e r n m e n t of
S a s k a t c h e w a n has p r o p o s e d a t w o
stage revision process, making some
changes n o w and conducting further
study
before
making
others.
The
N S S C / C C P E e x e m p t i o n c l a u s e w i l l be
c o n s i d e r e d d u r i n g t h e s e c o n d p h a s e of
this exercise.
In t h e m e a n t i m e , a
different e x e m p t i o n clause will pertain,
d i s c u s s i o n s c o n t i n u e w i t h B. R o b e r t s o n
t a k i n g t h e lead.
ALBERTA: We recently discovered that
the
Association
of
Professional
Engineers, G e o l o g i s t s a n d G e o p h y s i c i s t s
of A l b e r t a is e x p l o r i n g t h e p o s s i b i l i t y of
a s p e c i f i e d s c o p e of p r a c t i c e under its
A c t . This w o u l d allow s o m e w h o do
e n g i n e e r i n g - r e l a t e d w o r k b u t d o not
h a v e t h e required c r e d e n t i a l s f o r P.Eng.
s t a t u s t o o p e r a t e under t h e A c t . T h o s e
r e c e i v i n g s u c h s t a t u s w o u l d not be full
m e m b e r s of t h e A s s o c i t i o n a n d w o u l d
n o t h a v e final s a y o n t h e c o n d i t i o n s of
their registration. The CAP w r o t e to
urge t h e A s s o c i a t i o n t o first reduce the
n e e d f o r s u c h s t a t u s by i n c l u d i n g t h e
N S S C / C C P E e x c e m p t i o n c l a u s e in t h e i r
Act.
NSERC RELATED ACTIVITIES
T h e u p c o m i n g R e v i e w of P h y s i c s is a n
extremely important CAP response t o
the problems caused to
university
p h y s i c s by t h e last NSERC R e a l l o c a t i o n
exercise.
T h e C A P has s u b m i t t e d t w o m a j o r
p o s i t i o n p a p e r s t o NSERC: o n e o n t h e
R e l o c a t i o n process and one on the
Strategy
Implementation
Report.
R e c e n t i n f o r m a l i n d i c a t i o n s are t h a t
m a n y of t h e s u g g e s t i o n s in t h e C A P ' s
R e a l l o c a t i o n paper w i l l be f o l l o w e d n e x t
t i m e ; indeed, t h e future process may
h a v e m u c h in c o m m o n w i t h our R e v i e w
of P h y s i c s .
A C A P - N S E R C Liaison C o m m i t t e e has
been
established
and
has
been
o p e r a t i o n a l f o r a p p r o x i m a t e l y o n e year.
a f f e c t e d p a r t i e s , led by t h e
CAP
President,
P.S.
Vincett,
met
with
Dr. G e r r a r d t o d i s c u s s t h i s m a t t e r . A l s o
p r e s e n t w a s Paul S t o t t a r t w h o is o n t h e
political
staff
of
NRCan
Minister
McLellan. W e w e r e told that Minister
M a n l e y h a d w a n t e d t o a t t e n d but w a s
not able t o clear his c a l e n d a r . G e r r a r d
i n d i c a t e d t h a t he h a d b e e n a s k e d by
M a n l e y t o f i n d o u t m o r e on the issues
a n d t h a t he w o u l d g i v e h i m a f u l l
briefing.
W e continue to
pursue
meetings w i t h Ministers McLellan and
Manley. (We have been told informally
t h a t t h e r e is a g o o d c h a n c e M i n i s t e r
M c L e l l a n w i l l agree t o our r e q u e s t f o r a
meeting.)
D u r i n g t h e m e e t i n g w i t h Dr. Gerrard,
Dr.
Vincett
again
explained
the
community's
alarm
about
(i) t h e
u n i v e r s i t y r e s e a r c h i n f r a s t r u c t u r e issue,
a n d (ii) t h e N a t i o n a l F a c i l i t y p r o b l e m a n d
t h e lack of an i n t e g r a t e d p o l i c y f o r NFs.
He e x p l a i n e d h o w t h e o v e r a l l s i t u a t i o n
as a major n a t i o n a l crisis f o r l o n g - t e r m
research.
Dr. G e r r a r d i n d i c a t e d t h a t t h e y are n o w
l o o k i n g at a p r o g r a m t o s u p p o r t t h e
r e s e a r c h i n f r a s t r u c t u r e , a l t h o u g h (even
if t h e y are s u c c e s s f u l ) t h i s c o u l d not
see t h e light of day u n t i l t h e n e x t
b u d g e t . It is b e l i e v e d t h a t t h e l e t t e r s
t h e p h y s i c s c o m m u n i t y has already s e n t
t o t h e Prime M i n i s t e r are s t a r t i n g t o be
of c o n s e q u e n c e ; f u r t h e r p r e s s u r e f r o m
t h e c o m m u n i t y c o u l d play a crucial
role,
e s p e c i a l l y if t h e r e is o p p o s i t i o n t o t h e
program f r o m other Ministers.
N A T I O N A L F A C I L I T I E S (NFs)
A s y o u k n o w , t h e C A P is p a r t i c u l a r l y
urging action on the looming university
r e s e a r c h i n f r a s t r u c t u r e issue (arising
f r o m t h e r e d u c t i o n a n d r e d i r e c t i o n of
the federal transfer payments t o the
Provinces)
and
on the
threatened
N a t i o n a l Facilities.
T h e r e are s o m e
significantly encouraging signs that the
g o v e r n m e n t s e e m s t o be s t a r t i n g t o
notice
the
concern
of
the
CAP.
H o w e v e r , further pressure f r o m the
c o m m u n i t y is still e s s e n t i a l t o build o n
this.
W i t h i n t h e last m o n t h l e t t e r s h a v e b e e n
written
to
Ministers
Manley
and
McLellan
and
to
Dr. J o n G e r r a r d
r e g a r d i n g t h e i m p a c t of r e c e n t d e c i s i o n s
regarding funding t o Canada's national
s c i e n c e f a c i l i t i e s ( A t o m i c Energy of
Canada/Sudbury Neutrino Observatory,
the
Centre
Canadien
de
Fusion
M a g n e t i q u e , and the
Saskatchewan
Accelerator Laboratory). On 1996 May
2, representatives
of e a c h of
the
O n t h e NF i s s u e , Dr. G e r r a r d m a d e
some encouraging comments on the
N e u t r o n S c a t t e r i n g p o r t i o n of A E C L . In
t h e c a s e s of A E C L - T A S C C a n d C C F M ,
h o w e v e r , he w a s m u c h less s a n g u i n e ;
t h e g r o u p s e n s e d real c o n c e r n but also
f e l t t h a t t h e dollars m a y be t o o large f o r
I n d u s t r y C a n a d a t o pick up t h e s l a c k .
W h e n a s k e d if he w o u l d be w i l l i n g ( w i t h
M i n i s t e r M a n l e y ) t o help t h e C A P set up
a m e e t i n g b e t w e e n t h e M i n i s t e r of
F i n a n c e , s o m e of t h e f i v e C a n a d i a n
N o b e l L a u r e a t e s w h o are h e l p i n g t h e
C A P in t h i s c a m p a i g n , a n d P.S. V i n c e t t ,
Dr. G e r r a r d a g r e e d t o t r y t o help.
This g r o u p of r e p r e s e n t a t i v e s also m e t
w i t h t h e e d i t o r i a l page e d i t o r of T h e
O t t a w a Citizen. T h e C i t i z e n has c a r r i e d
a n u m b e r of s u p p o r t i v e articles a n d m a y
be w i l l i n g t o do m o r e . T h e C A P w a s
asked to provide more information on
t h i s issue a n d t o k e e p t h e m i n f o r m e d o n
future actions. Interestingly, the editor
felt that w i t h enough grass
roots
pressure this could become a major
55
public i s s u e , a n d t h a t if it d i d it c o u l d
radically
improve the
government's
approach t o research generally.
In o t h e r d e v e l o p m e n t s , t h e Bloc has
a s k e d a series of q u e s t i o n s in t h e H o u s e
o n C C F M (the T o k o m a k de V a r e n n e s ) ,
a n d t h e d e p u t y Premier of Q u e b e c
( M . L a n d r y ) has w r i t t e n t o t h e f e d e r a l
g o v e r n m e n t . T h e M o n t r e a l G a z e t t e has
c a r r i e d s u p p o r t i v e a r t i c l e s , a n d t h e NF
issue w a s on Quirks and Quarks on
M a y 4 t h . P.S. V i n c e t t w i l l , in t h e near
f u t u r e , be s e n d i n g a f u l l r e v i e w of t h e
w h o l e long-term research issue t o t h e
Globe and Mail. W e hope that this will
further
raise t h e
visibility
of
the
situation.
GENERAL
OBSERVATIONS
COMMENTS
AND
W h i l e t h e N a t i o n a l F a c i l i t y i s s u e is v e r y
s e r i o u s a n d u r g e n t , it r e p r e s e n t s o n l y
o n e a s p e c t of a m u c h m o r e s e r i o u s
problem: that t h e federal government
as a w h o l e (and t h e r e are h o n o u r a b l e
e x c e p t i o n s ) d o e s not really u n d e r s t a n d
t h e i m p o r t a n c e of l o n g - t e r m r e s e a r c h ,
a n d is p u r s u i n g policies w h i c h (perhaps
u n i n t e n t i o n a l l y ) are likely t o s e r i o u s l y
d a m a g e it. T h e i n f r a s t r u c t u r e issue is
perhaps t h e m o s t obvious example. W e
m u s t d r a w a 'line in t h e s a n d ' n o w a n d
s a y ' e n o u g h is e n o u g h ' . If w e d o not
d o t h i s , a n d if w e d o not d e f e n d
p h y s i c s w i t h o n e clear v o i c e , w e h a v e
b e e n t o l d m a n y t i m e s by p o l i t i c i a n s a n d
civil s e r v a n t s t h a t t h i n g s w i l l o n l y get
worse.
The whole community must
c o m e t o t h e d e f e n c e of w h i c h e v e r part
of us is under a t t a c k at a n y g i v e n
moment.
If w e w a i t u n t i l our o w n
i n s t i t u t i o n or our o w n t y p e of r e s e a r c h
is t h r e a t e n e d , t h e n t h e g o v e r n m e n t w i l l
s i m p l y play t h e g a m e of d i v i d e a n d
conquer. One senior civil servant said
t o t h e CAP some t i m e ago that ' w e can
pick s c i e n t i s t s o f f o n e at a t i m e ' .
To
p r e v e n t t h i s , w e m u s t s p e a k as o n e
c o m m u n i t y w h e n e v e r a k e y part of t h e
o v e r a l l f a b r i c of r e s e a r c h is t h r e a t e n e d .
In d e f e n d i n g s e v e r a l s p e c i f i c p a r t s of
the
community,
we
must
always
a d d r e s s b r o a d e r issues a n d a p p e a l t o
broader p r i n c i p l e s w h i c h all p h y s i c i s t s
c a n s u p p o r t . W e m u s t be v e r y c a r e f u l
not t o s u g g e s t t h a t s o m e o t h e r part of
research
be
sacrificed
to
support
a n o t h e r . T h e r e is no e v i d e n c e t h a t t h e
s i t u a t i o n is really a zero s u m g a m e .
A f t e r all, t h e f u n d s lost t o s c i e n c e as a
result of t h e a c t i o n s o n t h e n a t i o n a l
f a c i l i t i e s h a v e not b e e n t r a n s f e r r e d t o
NSERC! N o r , as far as w e are a w a r e ,
w a s there any significant impact on the
56
Physics in Canada
M arch/Aprill 9 9 6
rest of s c i e n c e w h e n T R I U M F r e c e i v e d
its r e n e w a l of f u n d i n g last y e a r .
The
f a c t is t h a t m o n e y c a n be f o u n d if t h e
government
is c o n v i n c e d t h a t
the
a r g u m e n t s re g o o d a n d t h a t e n o u g h
p e o p l e care. It is up t o C A P t o e n s u r e
t h a t t h e a r g u m e n t s are s t a t e d c l e a r l y .
H o w e v e r , it is up t o t h e c o m m u n i t y t o
m a k e s u r e t h a t e n o u g h p e o p l e speak
o u t in s u p p o r t t h a t t h e g o v e r n m e n t is
f o r c e d t o listen.
The CAP will continue t o do everything
in its p o w e r t o d e f e n d h i g h q u a l i t y
r e s e a r c h in all s e c t o r s f r o m t h e e f f e c t s
of f u t u r e b u d g e t c u t s .
T h e t a s k of
forming
the
next
generation
of
researchers, and t h e scientific
and
technical
leadership
of
tomorrow's
C a n a d a s h o u l d be a p r i m a r y o b j e c t i v e of
our society.
CAP'S t a s k is t o help
create
an environment
where
our
u n i v e r s i t i e s a n d our o t h e r o u s t a n d i n g
research institutions have t h e resources
necessary t o carry out these tasks.
CAP will continue t o w o r k tirelessly t o
these ends.
W e t h a n k all t h e C A P m e m b e r s (and
o t h e r s ) w h o h a v e w r i t t e n in s u p p o r t of
t h e CAP'S A p r i l l e t t e r t o t h e Prime
Minister.
W e are n o w s e e i n g t h a t
s u s t a i n e d a n d r e a s o n e d p r e s s u r e c a n be
heard. T h o s e w h o h a v e not w r i t t e n t o
Dr. G e r r a r d , M i n i s t e r M a n l e y , a n d t h e
other Ministers involved should give
serious consideration t o doing so n o w
(the f a x n u m b e r s are g i v e n b e l o w ) .
Equally i m p o r t a n t - as s t r e s s e d by
almost every government representative
w e h a v e m e t - call or w r i t e y o u r local
M P and M P P / M L A / M N A .
Emphasize
w h i c h e v e r issue is of m o s t c o n c e r n t o
y o u , or d i s c u s s t h e m b o t h , but l e t ' s
k e e p up t h e p r e s s u r e !
SCIENCE A N D T E C H N O L O G Y FOR T H E
N E W C E N T U R Y : A Federal S t r a t e g y
Response by the Partnership Group on
Science and Engineering
The government
of C a n a d a ' s
long
awaited document on science
and
technology focuses on evaluation and
management issues, w i t h considerable
emphasis on performance assessment,
in
government
departments
and
agencies. The socio-economic benefits
of c o m m e r c i a l i z a t i o n , a n d t h e j o b a n d
w e a l t h c r e a t i o n p o t e n t i a l of r e s e a r c h
a n d d e v e l o p m e n t are t h e c e n t e r p i e c e s
of t h e s t r a t e g y .
C o n s i d e r i n g t h e i m p r e s s i v e a m o u n t of
consultation
undertaken
by
the
Government
with
the
different
stakeholders
across
Canada,
the
Partnership A c t i o n Group for Science
a n d Engineering (PAGSE) h a d
high
expectations for a strategy document
w i t h a timetable for deliverables.
It
a n t i c i p a t e d a f o r m of " w h i t e p a p e r "
w i t h an a c t i o n plan f o r i m p l e m e n t a t i o n
of n e w t o o l s a n d n e w d i r e c t i o n s .
We
also e x p e c t e d t h e d o c u m e n t t o s p e c i f y ,
in a f i s c a l l y d e f i n e d s e n s e , t h e v a l u e
a n d s i g n i f i c a n c e of t h e f u l l s p e c t r u m of
r e s e a r c h (i.e., t h e c o n t i n u u m f r o m basic
to
applied)
and
development
for
e n h a n c i n g t h e q u a l i t y of life of o u r
c i t i z e n s . W h i l e t h e d o c u m e n t does not
a t t a i n t h e s e goals in a s u b s t a n t i v e w a y ,
P A G S E does e n t h u s i a s t i c a l l y e n d o r s e
s o m e of t h e p o i n t s m a d e in t h e r e p o r t .
These include the:
(613)
(a)
R e c o g n i t i o n of t h e need
for
c o n s t r u c t i n g a b r o a d b a s e of s c i e n t i f i c
e n q u i r y in all m a j o r f i e l d s of e n d e a v o u r .
Dr. Peter A d a m s , M P. (Chair, Liberal
Caucus
Committee
on
Higher
Education): (613) 9 9 6 - 9 8 0 0
(b)
Statement that "research, both
basic a n d a p p l i e d , p r o v i d e a c o n t i n u o u s ,
renewable
source
of
skills,
ideas,
t e c h n o l o g i e s , a n d policies . . . "
T h e Rt H o n .
941-6900
Jean
Chretien:
H o n . J o h n M a n l e y ( M i n i s t e r of I n d u s t r y ) :
( 6 1 3 ) 9 9 2 - 0 3 0 2 or 9 9 5 - 1 5 3 4
H o n . J o n G e r r a r d ( S e c r e t a r y of S t a t e
f o r S c i e n c e , R & D ) : ( 6 1 3 ) 9 9 0 - 4 0 5 6 or
947-4250
H o n . A n n e M c L e l l a n ( M i n i s t e r of N a t u r a l
R e s o u r c e s , w h i c h has r e s p o n s i b i l i t y f o r
AECL and CCFM): (613) 9 9 6 - 4 5 1 6
H o n . Paul M a r t i n :
995-5176
(613) 9 9 2 - 4 2 9 1
or
(c) S u p p o r t of f u n d i n g a n d p e r f o r m i n g
scientific research w i t h i n government
d e p a r t m e n t s a n d a g e n c i e s ; r e s e a r c h in
post-secondary institutions; corporate
r e s e a r c h a n d d e v e l o p m e n t ; c e n t e r s of
excellence.
(d) V i e w t h a t q u a l i t y s c i e n c e is c e n t r a l
t o sound policy development.
(e)
F o r m a t i o n of a n e w A d v i s o r y
Council on Science and Technology/
Innovation w h i c h w o u l d provide direct
input t o cabinet
on research
and
development and other priority issues.
P A G SE a n t i c i p a t e s t h a t t h e C o u n c i l w i l l
a d d r e s s s o m e of t h e c o n c e r n s of t h e
science community.
r e s e a r c h e r s w h o n e e d t o m a k e u s e of
t h e f a c i l i t i e s c a n n o t a f f o r d t o pay t h e
t e c h n i c a l s u p p o r t c o s t s r e q u i r e d t o get
the w o r k done!
(f)
Requirement
that
government
departments and agencies
establish
mechanisms
to
secure
external
assessment
of
the
extent
of
a c h i e v e m e n t of m i l e s t o n e s , a n d a d v i c e
on future programs and priorities.
C l e a r l y , in a c c o r d w i t h
II,
should
g o v e r n m e n t d e c i d e t h a t t h e r e is no
p r o s p e c t f o r a m a r k e d i n c r e a s e in t h e
f u n d i n g of r e s e a r c h in C a n a d a , in t h e
next 3 - 4 years, priority decisions must
be m a d e in a l l o c a t i n g r e s o u r c e s f o r
research
across
government
d e p a r t m e n t s , and amongst the three
principal granting councils. The planned
A d v i s o r y C o u n c i l ( s u b j e c t t o its d e t a i l e d
t e r m s of r e f e r e n c e ) or o t h e r bodies (i.e.
cross government departments, cross
granting
councils)
could
make
r e c o m m e n d a t i o n s in t h i s regard.
The
successful
British
example
of
a
T e c h n i c a l Foresight C o m m i t t e e m a y be
i n s t r u c t i v e in t h i s regard.
(g)
C r e a t i o n of
partnerships
and
networks
between combinations
of
individuals f r o m t h e private sector,
government, and universities.
S o m e of t h e c o n c e r n s
has i n c l u d e :
which
PAGSE
I.
S o m e of
the
positive
points,
e s p e c i a l l y a-d a b o v e , w h i l e l a u d a t o r y ,
are " m o t h e r h o o d s t a t e m e n t s " a n d are
not " f r o n t a n d c e n t e r " in t h e d o c u m e n t .
T h e s e s t a t e m e n t s w i l l not h a v e a n y
l a s t i n g v a l u e u n l e s s t h e r e is a s p e c i f i c
a l l o c a t i o n of r e s o u r c e s , c o n c u r r e n t w i t h
a draft plan for policy i m p l e m e n t a t i o n ,
d e v e l o p e d in c o n c e r t w i t h t h e S & T
community.
II. P A G S E is w e l l a w a r e of t h e e x i s t i n g
and anticipated budgetary constraints.
C o n s e q u e n t l y , a l t h o u g h all m a j o r f i e l d s
of e n d e a v o u r m e r i t s o m e s u p p o r t o n t h e
basis of e x c e l l e n c e , a l l o c a t i o n p r i o r i t i e s
m u s t be m a d e (by a p p r o p r i a t e b o d i e s
w h i c h serve the different communities
universities,
government,
corporate
s e c t o r ) t o a m u c h g r e a t e r e x t e n t a n d at
a m o r e d e t a i l e d level, t h a n
those
d e s c r i b e d in t h e s t r a t e g y d o c u m e n t .
III. C a n a d a lags far b e h i n d our m a j o r
c o m p e t i t o r s in t e r m s of p e r c e n t of G D P
i n v e s t e d in R & D. A s p o i n t e d out in
t h e Red B o o k , t h i s is largely t h e result
of u n d e r f u n d i n g f o r i n d u s t r i a l s c i e n c e
a n d t e c h n o l o g y by t h e p r i v a t e s e c t o r .
U n t i l r e s e a r c h a n d d e v e l o p m e n t is g i v e n
a h i g h e r p r i o r i t y by g o v e r n m e n t , C a n a d a
w i l l c o n t i n u e t o lose in t h e race f o r
technological competitiveness.
W h i l e t h e paper is c o m m e n d a b l e in
promoting
partnership
agreements,
collaborative
programs,
and
an
open-door
policy
for
laboratories,
n o w h e r e does it a d d r e s s t h e issue of
t h e u n d e r f u n d i n g of r e s e a r c h in C a n a d a .
A
partnership
between
two
u n d e r f u n d e d g r o u p s (eg., u n i v e r s i t i e s
and government research laboratories)
is not n e c e s s a r i l y a p r e s c r i p t i o n f o r
s u c c e s s . F u r t h e r m o r e , t h e r e is l i t t l e
p o i n t in g o v e r n m e n t l a b o r a t o r i e s h a v i n g
an o p e n - d o o r p o l i c y w h e n t h e u n i v e r s i t y
IV. W h i l e P A G S E is c o g n i z a n t of t h e
n e e d by g o v e r n m e n t t o e m p h a s i z e t h e
commercialization
of
science
and
t e c h n o l o g y , t h e g r o u p w a s s t r u c k by
the inattention (except s t a t e m e n t s a
a n d b a b o v e ) t o s p e c i f i c s o n basic
research
as
the
foundation
and
galvanizer for technology development
and
commercialization
of
new
processes,
as
well
as
for
the
m a n u f a c t u r e of n e w p r o d u c t s
(and
more economical routes t o existing
commercial items).
V.
A
major
impediment
to
the
c o m m e r c i a l i z a t i o n of C a n a d i a n r e s e a r c h
a n d d e v e l o p m e n t is t h e r e l u c t a n c e of
financial
institutions
to
provide
financing for late-stage development
a n d initial p r o d u c t i o n of n e w p r o d u c t s
of s m a l l a n d m e d i u m s i z e d e n t e r p r i s e s .
W h i l e p a r t i a l l y a d d r e s s e d by t h e S & T
S t r a t e g y , t h i s needs t o be r e c o g n i z e d as
a
continuing
problem
requiring
additional responses.
international S & T collaboration for t h e
b e n e f i t of C a n a d i a n f i r m s , l i t t l e is s a i d
concerning
the
collaboration
of
university and government researchers
o n a n i n t e r n a t i o n a l basis.
The cost
b e n e f i t a n a l y s i s t o our r e s e a r c h e r s , t h e
enhanced
opportunities
to
perform
c u t t i n g edge research, and the g o o d w i l l
s u c h c o l l a b o r a t i o n brings t o C a n a d a , are
s u b s t a n t i a l indeed.
T h e r e is no c e n t r a l f u n d t o e n c o u r a g e
a n d f o s t e r C a n a d i a n p a r t i c i p a t i o n in
i n t e r n a t i o n a l S & T. G i v e n t h e f a c t t h a t
NSERC has e l i m i n a t e d
international
programs,
that
other
government
a g e n c i e s a n d d e p a r t m e n t s (e.g. F o r e i g n
A f f a i r s ) h a v e also s i g n i f i c a n t l y r e d u c e d
t h e i r b u d g e t s in t h e s e c a t e g o r i e s , s o m e
a c k n o w l e d g e m e n t of t h e v i t a l i t y of
i n t e r n a t i o n a l c o l l a b o r a t i o n w a s in o r d e r ,
as
one
mechanism
for
Canadian
r e s e a r c h e r s t o c o m p e t e o n a global
basis.
VIII.
T h e o v e r r i d i n g c o n c e r n of t h e
d o c u m e n t is r e s e a r c h p e r f o r m a n c e a n d
a c c o u n t a b i l i t y in g o v e r n m e n t a g e n p i e s
and
departments,
with
only
a
" b r o a d - b r u s h " t r e a t m e n t of u n i v e r s i t y
research and, for that m a t t e r , research
a n d d e v e l o p m e n t in t h e p r i v a t e s e c t o r .
T h e l a t t e r t w o are c e n t r a l t o any
s u c c e s s f u l S & T s t r a t e g y leading t o j o b
creation and e c o n o m i c success.
IX.
T h e r e is a m a j o r c o n c e r n a b o u t
mechanisms
of
governance
and
p r o v i s i o n of S & T a d v i c e .
The
effectiveness
of
a
new
Advisory
Council on S & T / l n n o v a t i o n will heavily
depend
on
the
quality
of
its
m e m b e r s h i p . It w o u l d be i n a p p r o p r i a t e
to have such a Council selected entirely
f r o m t h e p r i v a t e s e c t o r (as has b e e n
s u g g e s t e d ) . In C a n a d a , p r i v a t e s e c t o r
r e s e a r c h a n d d e v e l o p m e n t is w e a k a n d
it w o u l d be u n f o r t u n a t e
if
strong
representation from practicing scientists
or e n g i n e e r s in t h e a c a d e m i c
and
government
communities
were
not
involved.
Also
an
international
p r e s e n c e w o u l d be v e r y u s e f u l .
V I . P A G S E agrees t h a t t h e I n f o r m a t i o n
Highway
is
a
valuable
tool
for
facilitating
communication
and
n e t w o r k i n g amongst researchers and
o t h e r s i.e. it c o n t r i b u t e s t o t h e r e s e a r c h
infrastructure. The strategy d o c u m e n t
g i v e s readers t h e i m p r e s s i o n t h a t t h e IH
is m o r e t h a n a t o o l .
Redundancies
r e s u l t i n g f r o m t h e e x p a n s i o n of t h e IH
w i l l in our v i e w be s u b s t a n t i a l l y , if not
c o m p l e t e l y , o f f s e t by t h e need t o c r e a t e
n e w positions for information analysis
and dissemination.
In c o n c l u s i o n t h e r e are, as in any
d o c u m e n t of t h i s t y p e , p o s i t i v e a n d
negative components. Some elements
VII. W h i l e t h e r e c o m m e n d a t i o n is m a d e
t h a t federal departments and agencies
develop
explicit
plans t o
promote
technology.
are
sensible,
realistic,
and
merit
follow-up.
This d o c u m e n t is o n e of
"process"
and
PAGSE
urges
the
d e v e l o p m e n t a n d i m p l e m e n t a t i o n of a n
"action plan."
W e are r e a d y t o w o r k
w i t h g o v e r n m e n t on this and other
issues of r e l e v a n c e t o s c i e n c e a n d
57
NEWS / NOUVELLES
MANLEY
ANNOUNCES
TWO
A P P O I N T M E N T S TO NSERC
On J a n u a r y 18, 1 9 9 6 , Industry Minister
J o h n M a n l e y announced the a p p o i n t m e n t
of A n g u s Bruneau and Julie Payette t o the
Natural Sciences and Engineering Research
Council (NSERC).
A n g u s A n d r e w Bruneau is the Chairman,
President and CEO of Fortis Inc.
The
holder of a d o c t o r a t e in Physical M e t a l l u r g y
f r o m the U n i v e r s i t y of London,
his
experience in business and academia is
v a s t . It includes 1 0 years w i t h M e m o r i a l
U n i v e r s i t y of N e w f o u n d l a n d and 7 years at
the U n i v e r s i t y of W a t e r l o o , and acting as
director of a w i d e v a r i e t y of companies
over the last t h i r t y years. Dr. Bruneau has
also served on c o m m i t t e e s and the boards
of several national and
international
research
and e c o n o m i c
development
organizations,
including
the
National
Research Council, NSERC, and the OECD.
Julie Payette w a s selected as a m e m b e r of
the Canadian A s t r o n a u t Program in 1 9 9 2 .
Building on a Bachelor's degree
in
Engineering f r o m McGill and a Master of
Applied Science f r o m the U n i v e r s i t y of
T o r o n t o , she is currently w o r k i n g t o w a r d s
a d o c t o r a t e in Electrical Engineering at
McGill. M s P a y e t t e ' s design and research
experience includes areas such as h u m a n
c o m p u t e r interfaces, speech processing in
adverse e n v i r o n m e n t s , and the application
of v o i c e t e c h n o l o g y t o space.
She has
w o r k e d w i t h IBM Canada and t h e Speech
Research Group at Bell-Northern Research.
M s Payette is one of t w o nominated
Canadian
specialists
on
the
NATO
International Research S t u d y Group on
speech processing.
NSERC 1 9 9 6 N A T I O N A L COMPETITION
RESULTS A N N O U N C E D
(Gov't of Canada Press Release dated Apr. 4/96)
Dr. T o m B r z u s t o w s k i , President of the
Natural Sciences and Engineering Research
Council of Canada (NSERC) in announcing
the results of the C o u n c i l ' s 1 9 9 6 national
c o m p e t i t i o n for research grants
and
scholarships ( 4 , 1 2 5 n e w a w a r d s totalling
$ 1 2 2 million) stated that "Our researchers
and u n i v e r s i t y training in research rank
a m o n g t h e best in the w o r l d , in t e r m s of
b o t h quality and p r o d u c t i v i t y . W e have in
this c o u n t r y developed excellent s y s t e m s
for assessing the quality of our research
a c t i v i t y , and w e k n o w that in all the
i m p o r t a n t areas of research Canadian
universities are achieving a great deal w i t h
resources t h a t are modest by international
standards."
Dr. B r z u s t o w s k i said the Council w a s
resuming the annual announcement of its
a w a r d s because of g r o w i n g public interest
in science and t e c h n o l o g y . " T o d a y , w e are
all v e r y conscious of the economic
implications of activities on w h i c h w e
spend public funds. Basic research is an
e x t r e m e l y important a c t i v i t y . It builds the
stock of k n o w l e d g e in our society.
But
p r o m o t i n g awareness of it and using the
results productively are equally necessary
activities."
A full list of the results of the 1 9 9 6 grants
c o m p e t i t i o n can be obtained f r o m NSERC's
W e b site on the Internet at h t t p : / / w w w .
nserc.ca/newsl .htm.
The Impact of the Research I n v e s t m e n t
•
REQUEST FOR PROPOSALS (RFP)
Technology
Development
Program
in
Intelligent S y s t e m s and Robotics
On
January
26,
1996,
PRECARN
A s s o c i a t e s Inc. issued a Request for
Proposal (RFP) for their next w a v e of
f u n d e d research programs. PRECARN in
association
with
CATA,
seeks
the
participation of industry m e m b e r s in its
industry-led,
collaborative
research
p r o g r a m . PRECARN w i l l c o n t r i b u t e up t o
4 0 % of eligible project costs (in intelligent
s y s t e m s and robotics) up t o $1 million,
inclusive of early stage c o m m e r c i a l i z a t i o n .
T o t a l i n v e s t m e n t s w i l l exceed $ 6 5 million
b e t w e e n 1 9 9 6 and 2 0 0 0 .
•
This RFP is open t o all PRECARN M e m b e r s
and t o n e w partners w h i c h c o m m i t t o
become PRECARN M e m b e r s , if their
projects are approved. Research areas are
classified in these categories: robotics,
machine sensing, h u m a n machine interface
and intelligent c o m p u t a t i o n .
C A T A is publicizing RFP i n f o r m a t i o n on its
T e c h n o g a t e W o r l d W i d e W e b databases
( h t t p : / / w w w . t e c h n o g a t e . c o m ) . Interested
parties should click on the T e c h n o g a t e
"Partners and A l l i e s " icon and search under
" R & D " or "PRECARN" or click on " H o t
Links"
and
then
"Research
and
Development."
58
Physics in Canada
M arch/Aprill 9 9 6
•
4 0 % of the annual t o t a l Canadian
industrial
investment
in
university
research is d i r e c t l y linked t o NSERC
f u n d i n g for basic and project research.
More t h a n 1 , 0 0 0 companies have
d i r e c t l y c o n t r i b u t e d over $ 3 0 0 million t o
date to u n i v e r s i t y projects, t h e m a j o r i t y
of w h i c h build on the o u t c o m e s of
earlier NSERC i n v e s t m e n t in basic
u n i v e r s i t y research.
Companies along the section of road in
Kanata that runs f r o m Digital t o
N e w b r i d g e N e t w o r k s Corp. produce
t o t a l annual sales in excess of $3 billion
- of w h i c h more than 8 0 % is f r o m
exports.
These f i r m s are highly
dependent o n the quality of y o u n g
recently
trained
engineers
and
scientists.
The companies employ
9,000
people
directly,
with
the
companies that service t h e m e m p l o y i n g
a further 2 7 , 0 0 0 .
Canada's largest
R & D p e r f o r m e r , Nortel, a t t r i b u t e s its
significant global success and f u t u r e
prospects t o its high i n v e s t m e n t in R&D
and t o the q u a n t i t y and quality of talent
recruited f r o m Canadian universities.
Surveys of the career status of previous
holders
of
NSERC's
national
scholarships c o n s i s t e n t l y indicate a very
l o w rate of u n e m p l o y m e n t (less t h a n
3 % , c o m p a r e d w i t h the current national
average of 9 . 6 % ) . T w o - t h i r d s of these
graduates are active in R & D .
A
significant proportion of the others are
involved full t i m e in such professional
activities
as
teaching,
product
development,
consulting,
and
management.
More i n f o r m a t i o n about the impact of
NSERC-assisted research and training can
be f o u n d on their W e b Site in the
publication Research Means
Business.
PUBLIC HEARINGS FOR NUCLEAR FUEL
W A S T E M A N A G E M E N T A N D DISPOSAL
CONCEPT A N N O U N C E D
Public hearings t o r e v i e w A t o m i c Energy of
Canada L i m i t e d ' s proposed nuclear fuel
w a s t e management and disposal concept
w e r e held in T o r o n t o , Pickering, Thunder
Bay, Sudbury and Chalk River f r o m M a r c h
through May, 1996.
On February 1,
1 9 9 6 , a detailed schedule for the hearings
w e r e released by the federal e n v i r o n m e n t a l
assessment panel r e v i e w i n g the w a s t e
management and disposal c o n c e p t .
Phase I hearings t o o k place in T o r o n t o and
Pickering, M a r c h 11-15 and 2 5 - 2 9 , 1 9 9 6
and Thunder Bay, Sudbury and Chalk River
f r o m April 2 9 t o M a y 2, 1 9 9 6 . This phase
focused on the presentation and roundtable discussion of broad societal issues
related t o the long-term m a n a g e m e n t of
nuclear fuel w a s t e . Discussion papers are
available on request f r o m the panel
secretariat.
Phase II hearings, t o take place in T o r o n t o
f r o m J u n e 1 0 - 1 4 and 1 7 - 2 1 , 1 9 9 6 w i l l
consist of technical sessions f o c u s i n g on
the long-term safety of the A t o m i c Energy
of Canada L i m i t e d concept of geologic
disposal f r o m scientific and engineering
v i e w p o i n t s . More i n f o r m a t i o n concerning
these w i l l be available at a later date.
Phase
III
hearings
will
consist
of
c o m m u n i t y visits in N e w
Brunswick,
Quebec,
Ontario,
Manitoba
and
S a s k a t c h e w a n w h e r e participants w i l l have
an o p p o r t u n i t y t o provide their final
opinions and v i e w s on the s a f e t y and
acceptability of the concept for disposal of
nuclear fuel w a s t e including any other
issues relevant t o the panel's mandate.
The schedule w i l l be announced later.
For more i n f o r m a t i o n , please c o n t a c t
Ghislaine
Kerry
by
telephone
at
(819)953-0179
(collect), by fax
at
(819) 9 9 4 - 1 4 6 9
or
by
internet
at
Kerryg@fox.nstn.ca.
D O C U M E N T ORDERING O N THE W O R L D
WIDE WEB
The W o r l d W i d e W e b o f f e r s CISTI clients
an additional electronic d o c u m e n t ordering
m e t h o d . Because orders s u b m i t t e d by this
method
flow
directly
into
CISTI's
automated
document
delivery
s y s t e m , p r o c e s s i n g c o s t s are reduced.
CISTI passes these c o s t savings on t o
clients in the f o r m of l o w e r service fees.
A n y registered CISTI client w i t h access to
the W o r l d W i d e W e b can order d o c u m e n t s
this w a y .
You need a CISTI account
number beginning w i t h the prefix FGH, W K
or DD, plus a p a s s w o r d . All clients w i t h
the FGH and W K a c c o u n t s already have a
p a s s w o r d ; m o s t clients w i t h a DD account
do not. To obtain a p a s s w o r d for a DD
a c c o u n t , or t o register as a n e w client,
please c o n t a c t CISTI's Client Registration
at:
Phone:
( 6 1 3) 9 9 8 - 8 5 4 4
or
1 - 8 0 0 - 6 6 8 - 1 2 2 2 Fax: (613) 9 5 4 - 2 2 1 7
E-mail: c c r s @ c i s t i . l a n . n r c . c a
To register electronically, fill out the Client
Registration Form f o u n d on the W e b at
www. cisti. nrc. ca/ cisti/register.
html
FREE ACCESS
TO
CISTI'S
ONLINE
CATALOGUE
A c c e s s t o t h e online catalogue of the
Canada
Insitute
for
Scientific
and
Technical I n f o r m a t i o n (CISTI) is n o w
available free using the Internet.
The
catalogue is a listing of titles for all major
publications (serials, books, conference
proceedings, reports) in the fields of
science,
technology,
engineering
and
medicine w o r l d w i d e . It is updated every
w e e k . Those w h o do not use the Internet
t o access the online catalogue w i l l pay a
t e l e c o m m u n i c a t i o n s charge.
CISTI's online catalogue can also be used
t o order copies of the full t e x t s of these
publications, but y o u m u s t be registered
w i t h CISTI t o place an order. M o s t orders
are filled w i t h i n 2 - 3 d a y s , or there is a
4-hour urgent service available.
Both registered and non-registered clients
can also access the catalogue on the
W o r l d W i d e W e b at w w w . c i s t i . n r c . c a /
cisti/. To ensure a s u c c e s s f u l c o n n e c t i o n
to the CISTI Online Catalogue, W e b users
m u s t c o n f i g u r e their Telnet s o f t w a r e t o
w o r k w i t h their b r o w s e r (eg. Netscape,
M o s a i c , etc.)
NSERC C A N C E L S CPG PROGRAM
(Contact Vol.20(3), Written 1995)
At
its m e e t i n g
in O c t o b e r ,
NSERC
approved
the
phase-out
of
the
Collaborative
Project
Grants
(CPG)
p r o g r a m , as r e c o m m e n d e d by the Strategy
I m p l e m e n t a t i o n Task Force.
Although
there w i l l be no more c o m p e t i t i o n s ,
c o m m i t m e n t s made in the 1 9 9 4 and 1 9 9 5
c o m p e t i t i o n s w i l l be respected. Given the
financial e n v i r o n m e n t projected for the
c o m i n g years, it w a s clear t h a t resources
w o u l d not be s u f f i c i e n t t o allow the CPG
program t o achieve its objectives, and that
C o u n c i l ' s e f f o r t s w o u l d be better spent in
encouraging
collaboration
across
all
programs.
Reiterating its c o m m i t m e n t to collaborative
research, Council m a n d a t e d staff t o w o r k
closely w i t h the research c o m m u n i t y t o
ensure t h a t practices b o t h in the peer
r e v i e w process and in the universities
p r o m o t e the e m e r g e n c e of
excellent
collaborative proposals. A s a first step,
the d i s t i n c t i o n b e t w e e n NSERC individual
and t e a m
Research Grants w i l l
be
r e m o v e d . Staff w a s also encouraged t o
develop closer ties w i t h universities to t r y
t o break d o w n barriers t o collaboration
arising f r o m the u n i v e r s i t y p r o m o t i o n and
tenure process.
Council t o o k another significant
step
t o w a r d s
i m p l e m e n t i n g
the
recommendations
of
the
Strategy
I m p l e m e n t a t i o n Task Force by approving
the regrouping of activities in the Targeted
Programs area.
The n e w
Research
Partnerships Program has three main
c o m p o n e n t s : Strategic Projects, UniversityIndustry Projects and Research N e t w o r k s .
Council and staff are c o n t i n u i n g to w o r k
on suggestions for i m p l e m e n t i n g the Task
Force's
recommendations
regarding
NSERC's Scholarships programs,
and
A c c o u n t a b i l i t y and C o m m u n i c a t i o n s .
I n f o r m a t i o n on the i m p l e m e n t a t i o n of the
Task Force's r e c o m m e n d a t i o n s w i l l be
available t h r o u g h Contact
and NSERC's
W e b Site ( h t t p : / / w w w . n s e r c . c a ) .
TELLING THE RESEARCH STORY ( f r o m
U n i v e r s i t y A f f a i r s , M a r c h 1996)
T o m B r z u s t o w s k i is not afraid of straight
talk.
A n d he t h i n k s i t ' s crucial t h a t
Canadian u n i v e r s i t y researchers get just as
fired up about c o m m u n i c a t i o n s as he is.
" C o m m u n i c a t i o n s is a short t e r m and a
long
term
priority
for
me,"
says
Dr. B r z u s t o w s k i , w h o took over the helm
at the Natural Sciences and Engineering
Research Council last September after a
career
as
a
university
researcher,
administrator and senior provincial civil
servant. " A t every o p p o r t u n i t y that arises,
we
w i l l explain w h a t
the
research
c o m m u n i t y does in a w a y w h i c h is
interesting
and
memorable,
giving
e x a m p l e s , giving illustrations of o u t c o m e s ,
and all in plain language, not j a r g o n . "
In t i m e s of shrinking resources, u n i v e r s i t y
professors can no longer a f f o r d t o stay
cloistered in their research labs or isolated
in their c l a s s r o o m s . Instead, t h e y have t o
be prepared continually t o explain w h a t
t h e y do, j u s t i f y it, and t h e n c o n v i n c e a
jaded and t a x - w e a r y
public
of
the
i m p o r t a n c e of f u n d i n g it.
"Take
nothing
for
granted,"
Dr.
B r z u s t o w s k i tells researchers.
"Just
because w h a t y o u are doing is v e r y , v e r y
g o o d , i t ' s elegant and i t ' s i m p o r t a n t in your
discipline, and just because i t ' s already
being f u n d e d , d o e s n ' t mean t h a t a n y b o d y
is interested
in it outside of
your
discipline."
The d a y s w h e n researchers c o u l d v i e w any
media questions or politicians' inquiries
about their research as an u n w e l c o m e
intrusion or interference are gone, Dr.
B r z u s t o w s k i adds. "The a t t i t u d e t h a t
s o m e h o w the q u a l i t y of your w o r k is
s u f f i c i e n t to j u s t i f y w h a t e v e r a m o u n t of
support you get - that w a s a very nice
a t t i t u d e t o have. But resources c a n ' t keep
up w i t h t h a t . "
Dr. B r z u s t o w s k i ' s career path has left him
equipped t o understand the point of v i e w
of both u n i v e r s i t y professors and political
leaders.
A professor of mechanical
engineering at the U n i v e r s i t y of W a t e r l o o
for 25 years, he also served as vicepresident, academic, and provost of the
university.
A f t e r leaving the academic
w o r l d , he w a s appointed d e p u t y minister
of colleges and universities in Ontario, then
d e p u t y minister of the Premier's Council of
Ontario, a body charged w i t h developing
strategic policy advice t o the g o v e r n m e n t .
But he says it w a s his stint in the
u n i v e r s i t y classroom that n o w serves him
best.
" I t ' s amazing h o w 25 years of
c l a s s r o o m t e a c h i n g , particularly teaching in
the
lower
years
of
undergraduate
education, can alert y o u t o c o m m u n i c a t i n g
in simple t e r m s .
I t ' s nice t o t e a c h a
graduate course in your o w n jargon. But
w h e n y o u ' r e facing intelligent questions in
simple t e r m s , f r o m people w h o h a v e n ' t
learned the jargon y e t , t h e n y o u have t o
scramble."
Eventually he hopes the result of his
crusade t o f o c u s public a t t e n t i o n on
science and engineering w i l l be increased
public understanding
- and
financial
support - for u n i v e r s i t y research. "I w o u l d
like t o see w i d e s p r e a d recognition in this
c o u n t r y , and great c o n v i c t i o n , that it is
essential t o invest in research, science and
technology
and graduate training
of
researchers, just for the good of the
c o u n t r y , " he declares. "I really w o u l d like
t o see research considered as s o m e t h i n g
essential to Canada, and not as just a sop
to the egos of academics, not as just
another kind of social c o n s u m p t i o n , but
s o m e t h i n g that is the m e c h a n i s m by w h i c h
w e build the f u t u r e . "
The
communications
challenge
is
particulary i m p o r t a n t these days, w i t h
u n i v e r s i t y researchers squeezed by multiple
pressures.
Science and engineering
disciplines are breaking n e w ground; ideas
and n e w directions for investigation are
emerging daily. At the same t i m e , granting
council budgets are decreasing,
and
operating grants f r o m the provinces t o
universities, w h i c h help pay the costs of
u n i v e r s i t y research i n f r a s t r u c t u r e such as
libraries or laboratories, are also on the
decline.
In order t o cope,
many
researchers are t u r n i n g t o NSERC w i t h
requests t o fill the gap, t o provide funding
out
of
operating
grants
to
equip
laboratories or pay for other infrastructurerelated c o s t s .
"It seems t h a t , increasingly, grantees are
facing universities that are asking t o be
paid for the (research i n f r a s t r u c t u r e ) ,
because universities can no longer a f f o r d
t o provide these things for free. So w e ' r e
g e t t i n g a trickle, turning into a f l o w , and
probably a flood of r e q u e s t s " t o spend
NSERC m o n e y on research i n f r a s t r u c t u r e .
But such requests have a direct impact on
the b o t t o m line. "Every t i m e w e do t h a t ,
there is less m o n e y available for other
things."
Dr. B r z u s t o w s k i says he is b e c o m i n g
increasingly concerned that NSERC f u n d i n g
is being seen on c a m p u s e s as the sole
source
of f u n d i n g
for
science
and
engineering research. A n d he's w o r r i e d
59
that,
sooner
or
later,
university
a d m i n i s t r a t o r s m a y refuse t o sign NSERC
grant applications, including those for
major e q u i p m e n t , on behalf of their
researchers,
because
the
institutions
simply
can't
afford
to
supply
the
i n f r a s t r u c t u r e needed.
But a l t h o u g h NSERC officials are w o r r i e d ,
i t ' s d i f f i c u l t t o t r a c k h o w m u c h impact any
c r u m b l i n g in u n i v e r s i t y i n f r a s t r u c t u r e is
having. Dr. B r z u s t o w s k i fears the e f f e c t s
may
show
up
first
in
decreased
applications for NSERC g r a n t s . " W e w o n ' t
begin t o see this until the grant selection
c o m m i t t e e s begin t o point t o it, m a y b e not
in t h i s y e a r ' s c o m p e t i t i o n , m a y b e only in
next y e a r ' s . But if, in key areas in the
basic disciplines, holes d e v e l o p , not just in
t h e capabilities of individual i n s t i t u t i o n s ,
but across t h e c o u n t r y , t h e n no a m o u n t of
n e t w o r k i n g w i l l be able t o p a t c h t h a t up.
A n d as a national agency w e ' r e going t o
become v e r y concerned about i t . "
Dr. B r z u s t o w s k i says he is interested in
proposals - s u c h as one made recently by
the
Association
of
Universities
and
Colleges of Canada - t h a t w o u l d see the
federal g o v e r n m e n t pay d i r e c t l y for the
i n f r a s t r u c t u r e c o s t s of t h e research it
sponsors, rather t h a n relying on transfer
p a y m e n t s t o the provinces.
But s u c h a proposal, t o o , raises a
communications
challenge,
Dr. B r z u s t o w s k i
notes.
How
will
universities c o n v i n c e t h e public t h a t s u c h
a m o v e does not represent increased
budgets f o r the g r a n t i n g c o u n c i l s , but
rather s i m p l y s h i f t s the m e t h o d
of
allocating the funding? "The issue isn't
doubling the c o u n c i l s ' budgets, i t ' s finding
the other half of research c o s t s . T h a t has
t o be c o m m u n i c a t e d w i t h p r e c i s i o n , " Dr.
B r z u s t o w s k i says, " O t h e r w i s e t h e public
w o u l d be right t o reject the m o v e . "
A l t h o u g h c o m m u n i c a t i o n s w i t h the general
public
is
evidently
his
priority.
Dr. B r z u s t o w s k i is clear he also intends t o
build bridges t o the u n i v e r s i t y research
c o m m u n i t y . In f a c t , he makes it a point
not t o d i s t i n g u i s h b e t w e e n the g r a n t i n g
c o u n c i l and the c o m m u n i t y . "I see NSERC
as almost an organ of the c o m m u n i t y , " he
says.
"I d o n ' t see it as having goals
d i s t i n c t f r o m t h e research c o m m u n i t y . It
really is a v o i c e of t h e c o m m u n i t y . "
But, he a d m i t s , in the past there may w e l l
have
been
some
communication
b r e a k d o w n s b e t w e e n the g r a n t i n g council
and a number of u n i v e r s i t y researchers.
A n d , after several m o n t h s on the j o b and
v i s i t s t o several u n i v e r s i t y c a m p u s e s , he is
surprised h o w little some professors k n o w
about h o w NSERC is f u n d e d and h o w it
c o n d u c t s its business. Some professors,
for e x a m p l e , c o n t i n u e t o believe t h a t
NSERC council m e m b e r s g i v e up their
academic careers and m o v e t o O t t a w a
o n c e t h e y are appointed.
Surprisingly,
s o m e f a c u l t y are also u n a w a r e of the
volunteer
commitment
needed
from
a c a d e m i c s across Canada t o m a i n t a i n t h e
granting c o u n c i l ' s peer r e v i e w process.
60
Physics in Canada
M arch/Aprill 9 9 6
In building up t r u s t b e t w e e n NSERC and
the academic c o m m u n i t y , Dr. B r z u s t o w s k i
believes it is important t o allay researchers'
c o n c e r n s that NSERC m a y be t u r n i n g its
back on basic research. "I think one of the
things that the c o m m u n i t y w i l l need t o be
i n f o r m e d about, and t o become less
anxious about, is the notion that s o m e h o w
there is room w i t h i n NSERC for b o t h kinds
of research, b o t h the basic research and
project research."
One problem may be t h a t researchers fear
t h a t NSERC w i l l take a "one size f i t s all"
approach
to
science,
a
fear
Dr.
B r z u s t o w s k i says is groundless.
Too
o f t e n , he notes, applied or project-based
researchers fear t h a t the values of basic
research - c o u n t i n g the number
of
publications, for example - w i l l be applied
t o t h e m , w h i l e basic researchers w o r r y
t h e y w i l l be asked t o d e m o n s t r a t e the
i m m e d i a t e e c o n o m i c relevance of their
work.
In f a c t , says Dr. B r z u s t o w s k i , NSERC w i l l
apply "appropriate measures" t o each
a c t i v i t y . In the m e a n t i m e , he calls for a
kind of t r u c e b e t w e e n f a c u l t y involved in
basic research and those w o r k i n g on
applied projects.
" L e t ' s not create
anxieties w h e r e t h e y d o n ' t have t o be
c r e a t e d . " he urges researchers. " L e t ' s not
have any sneering across the interface ...
y o u k n o w , w e l l , w h a t y o u do is irrelevant,
and w h a t you do is not intellectual
enough."
Dr. B r z u s t o w s k i says he is o p t i m i s t i c such
d i f f e r e n c e s b e t w e e n researchers can be
w o r k e d out - just as he is o p t i m i s t i c that
decision-makers w i l l eventually heed his
message
about
the
importance
of
university
research
in
science
and
engineering.
" L e t ' s put it this w a y , " he explains. " I ' v e
had nobody c o m e around and tell me
t h e r e ' s good n e w s for NSERC in the next
(federal) budget. But on the other hand,
I ' v e met an increasing number of elected
officials here in O t t a w a w h o a c k n o w l e d g e
t h e i m p o r t a n c e of u n i v e r s i t y research
f u n d i n g . N o w at s o m e stage of the g a m e ,
s o m e t h i n g ' s got t o g i v e . "
UNIVERSITY NEWS /
ÉCHOS DES UNIVERSITÉS
COOPERATIVE
EFFORTS
FUND
RESEARCH
{University of Toronto Medal Release January 25/96)
Cooperative e f f o r t s b e t w e e n the N a t i o n a l
Sciences and Engineering Research Council
(NSERC),
international
technology
c o m p a n y Lumonics, Inc. and the U n i v e r s i t y
of T o r o n t o are helping ensure t h a t one of
Canada's
most
important
"natural"
resources remains in Canada.
D w a y n e Miller, a t o p researcher in laser
t e c h n o l o g y , has returned t o his native
Canada after several years in the United
States t o join the U n i v e r s i t y of T o r o n t o as
t h e holder of t h e NSERC-Lumonics Chair in
Quantum Optics.
His return f o l l o w s more t h a n 1 1 years at
the U n i v e r s i t y of Rochester w h e r e he
c o n d u c t e d pioneering research in solidstate laser t e c h n o l o g y and s p e c t r o s c o p y .
A l t h o u g h he w a s born in Canada and
received his BSc (honours) degree f r o m the
U n i v e r s i t y of Manitoba, he says t h e United
States
provided
greater
research
opportunities, especially for n e w f a c u l t y .
"Canada
has
not
been
willing
to
s u f f i c i e n t l y invest in their y o u n g s c i e n t i s t s
and
consequently
has
lost
some
o u t s t a n d i n g t a l e n t , " says Miller. "I w a s
really impressed by the level of support
and enthousiasm generated by L u m o n i c s ,
NSERC and the U n i v e r s i t y of T o r o n t o t o
reverse the trend. This w a s an o p p o r t u n i t y
t o make a d i f f e r e n c e t o Canadian science
I could not r e f u s e . " In the U.S., Miller w a s
a recipient of an NSF Presidential Y o u n g
Investigator A w a r d , D r e y f u s TeacherScholar
Fellowship,
A l f r e d P. S l o a n
F e l l o w s h i p and his research w a s f u r t h e r
supported
by
the
National
Science
Foundation, National Institute of Health,
and the D e p a r t m e n t of Energy.
INTERNATIONAL
NEWS/
NOUVELLES INTERNATIONALES
A LIGHT NIGHT READING?
(IOP Press Release, undated)
Researchers w o r l d w i d e can n o w gain
online access t o d e v e l o p m e n t s at the
f r o n t i e r s of physics f r o m the c o m f o r t of
their o w n desks, 2 4 hours a d a y , seven
days a week.
In a major international initiative, t h e UKbased Institute of Physics Publishing is
making all its research journals available on
the
Internet
to
scientists
whose
institutions
subscribe
to
the
well
established paper versions of the journals.
Not
only
will
articles
be
available
electronically up t o three w e e k s before
t h e y appear in print, researchers w i l l also
be able t o access t h e m via the W o r l d W i d e
W e b at no extra c o s t .
The journals produced by Institute of
Physics Publishing c o v e r the full g a m u t of
physics research, w i t h t o p i c s as diverse as
nanotechnology,
plasma
physics,
physiological m e a s u r e m e n t , nonlinearity
and the public understanding of science.
The Institute of Physics Publishing journals
n o w available on the W e b are: Journal of
Physics
A: Mathematical
and
General;
Journal of Physics B: Atomic,
Molecular
and Optical Physics; Journal of Physics D:
Applied
Physics;
Journal
of Physics
G:
Nuclear and Particle Physics; Journal
of
Physics Condensed Matter;
Measurement
Science and Technology;
Classical
and
Quantum
Gravity;
European
Journal
of
Physics; Nonlinearity;
Physics in Medicine
and
Biology;
Plasma
Physics
and
Controlled
Fusion;
Pure
and
Applied
Optics;
Semiconductor
Science
and
Technology;
and Superconductor
Science
and
Technology.
Further i n f o r m a t i o n and d e m o n s t r a t i o n
material is available at h t t p : / / w w w . i o p . o r g
CANADIAN PHYSICISTS /
PHYSICIENS ET PHYSICIENNES
Excellence in T e a c h i n g A w a r d s
(Extract from Simon Fraser News, Feb. 8/96)
H o w a r d T r o t t i e r , p h y s i c s , w a s selected as
one of the three w i n n e r s of
SFU's
excellence in t e a c h i n g a w a r d s this year. In
an i n t e r v i e w w i t h S i m o n Fraser N e w s
reporters, Dr. T r o t t i e r had the f o l l o w i n g t o
say about his teaching ...
A r e there any special techniques y o u use
to motivate your students?
D e m o n s t r a t i o n s . T h e y ' r e a big part of
teaching
physics,
at
least
in
our
department.
A c t u a l l y measuring the
acceleration of a ball as i t ' s dropping w i l l
a l w a y s be more c o n v i n c i n g t h a n w o r k i n g it
out t h r o u g h equations. Things like that
resonate w i t h s t u d e n t s . O f t e n w h e n I ' m
w h e e l i n g equipment d o w n a h a l l w a y I can
see t h a t s t u d e n t s are genuinely e x c i t e d
that t h e r e ' s going t o be a d e m o n s t r a t i o n in
m y lecture that day.
In y o u r opinion, w h a t are t h e t o p three
qualities t h a t make a g o o d teacher?
Teachers need t o project themselves
- to
make eye c o n t a c t w i t h s t u d e n t s in the
back r o w . I like t o get right in the middle
of a class and j u m p up and d o w n . A n d I
make no apology for p u t t i n g e n t e r t a i n m e n t
value in m y lectures. Second, teachers
have t o be accessible.
I have open o f f i c e
hours. If I ' m on c a m p u s , s t u d e n t s can ask
me q u e s t i o n s a n y t i m e .
A n d like other
f a c u l t y in t h e physics d e p a r t m e n t , I d r o p
by our open labs t o make myself available
t o s t u d e n t s in an i n f o r m a l w a y as o f t e n as
possible. Finally, e v e r y o n e appreciates a
good joke in class: 'Physics h u m o u r ' , as
m y w i f e calls it, because o f t e n t h e joke
isn't f u n n y outside the lecture.
For
e x a m p l e , I f o u n d a clip f r o m Star Trek in
w h i c h Captain Kirk and Spock are t a l k i n g
about a n t i - m a t t e r . I t ' s b e c o m e part of m y
teaching arsenal. I play the video in class
after t e a c h i n g the subject. Students can
spot w h a t ' s w r o n g i m m e d i a t e l y as the
characters w o r r y that if Lazarus meets his
a n t i - m a t t e r t w i n , it w i l l be the end of life
as w e k n o w it.
The o v e r a c t i n g and
o v e r d r a w n music add to the hilarity of the
c o n v e r s a t i o n , so it w o r k s very w e l l in
class.
W h a t challenges do y o u e x p e c t t o c o n f r o n t
as a teacher in t h e i m m e d i a t e future?
It m a y be inevitable t h a t class size w i l l
increase because of c u t b a c k s and d e m a n d .
I think big classes are a serious problem.
They
make
students
feel
totally
anonymous.
In m y experience, smaller
classes (even in the 1 0 0 - 2 0 0 student
range) provide for more teacher-student
c o n t a c t . For t h e physics d e p a r t m e n t , l o w
e n r o l m e n t , particularly in the upper levels,
has t o be addressed,
if w e expect t o
a t t r a c t more s t u d e n t s , t h e y have t o be
able t o get jobs. This is a problem w h i c h
m y d e p a r t m e n t is t a k i n g seriously.
W h a t advice w o u l d y o u g i v e t o s o m e o n e
just s t a r t i n g their career as a u n i v e r s i t y
teacher?
Be e n t h u s i a s t i c .
Search for
s o m e t h i n g great in the smallest detail and
CANADIEN(NE)S
d o n ' t be shy about pointing it out.
S t u d e n t s should k n o w t h a t y o u really w a n t
t o be there.
starting t o address the q u e s t i o n of w h a t
this means for the electrical and magnetic
properties of these m a t e r i a l s . "
M c M a s t e r U n i v e r s i t y Researcher Captures
National Science and Engineering Prize
It w a s only by chance t h a t Dr. Kallin, n o w
recognized as one of the t o p condensed
m a t t e r theorists in the w o r l d , got into
physics.
In high school she dropped
physics after Grade 10.
It w a s a
c o m m u n i t y college course in " p h y s i c s for
p o e t s " that piqued her interest in the
subject and led her t o the honours physics
program at the U n i v e r s i t y of British
Columbia.
On 1 9 9 6 J a n u a r y 17 Dr. T o m B r z u s t o w s k i ,
President of the Natural Sciences and
Engineering Research Council of Canada
(NSERC) announced the w i n n e r s of some
of the c o u n t r y ' s m o s t prestigious a w a r d s .
Recipients w e r e selected f r o m nominations
f r o m universities across Canada.
Four o u t s t a n d i n g professors w i l l receive
the
1996
E.W.R. Steacie
Memorial
Fellowships.
"These individuals are
creating
international
recognition
for
Canada in some of the most e x c i t i n g fields
of
science
and
engineering,"
said
Dr. B r z u s t o w s k i .
" T h e y underline the
e x t r a o r d i n a r y high calibre of research and
training in Canadian u n i v e r s i t i e s . "
Dr. Catherine Kallin is an o u t s t a n d i n g
scientist in the D e p a r t m e n t of Physics,
McMaster
University.
She
has
d e m o n s t r a t e d exceptional leadership and
a c c o m p l i s h m e n t in theoretical solid state
p h y s i c s , particularly in the t h e o r y of high
temperature superconductors.
Other recipients include Dr. Ming Li,
mathematician
at
the
University
of
Waterloo,
Dr. J e d H a r r i s o n
of
the
D e p a r t m e n t of C h e m i s t r y , U n i v e r s i t y of
Alberta,
and
Dr. Demetri Terzopoulos,
Department
of
Computer
Science,
U n i v e r s i t y of T o r o n t o .
The NSERC a w a r d s provide the recipients
w i t h an o p p o r t u n i t y t o expand their
research p r o g r a m s and o b t a i n additional
research assistance. The prizes w i l l be
o f f i c i a l l y presented in J u n e along w i t h the
Canada Gold Medal for Science and
Engineering.
Short A r t i c l e on Dr. Kallin
M c M a s t e r U n i v e r s i t y physics professor
Catherine Kallin and her collaborators have
been s t u d y i n g m i c r o w a v e m e a s u r e m e n t s
on high-temperature s u p e r c o n d u c t o r s , and
using the data t o d e t e r m i n e the electrical
and
magnetic
properties
of
these
s u p e r c o n d u c t o r s and t o understand w h y
the materials are s u p e r c o n d u c t o r s at all.
"Our
traditional
understanding
of
s u p e r c o n d u c t o r s , w h i c h w e r e d i s c o v e r e d in
1 9 1 1 , strongly suggests that superconduct i v i t y s h o u l d n ' t exist above 3 0 degrees
A b s o l u t e ( - 2 4 3 degrees Celsius)," explains
Dr.
Kallin.
But
high-temperature
superconductivity
(above 3 0
degrees
Absolute) w a s d i s c o v e r e d in 1 9 8 6 , and in
subsequent
years
the
temperature
escalated t o the present record of 1 6 0
degrees A b s o l u t e ( - 1 1 3 degrees Celsius).
" T h e r e ' s a large body of evidence that
points to electron-electron interactions as
the
cause
of
high-temperature
superconductivity.
But w e ' r e just n o w
(For more i n f o r m a t i o n on Dr. Kallin, see the
family
profile
on
Dr.
Kallin
and
Dr. Berlinsky w h i c h appears later in this
issue.)
NEWS FROM
MEMBERS
CORPORATE
L'INO FAIT UN DON D'ÉQUIPEMENT A U
CÉGEP DE LA POCATIÈRE
Le président-directeur général de l ' I n s t i t u t
national
d'optique
(INO),
monsieur
Jean-Guy Paquet, a été très heureux
d'annoncer
le
20
février
1996
à
La Pocatière, le d o n par l'INO au Cégep de
la Pocatière, du s y s t è m e d ' é c r i t u r e FAB
pour des fins d ' e n s e i g n e m e n t et de
f o r m a t i o n des étudiants en technologie
physique.
Ce
don
a
été
possible
suite
au
r e m p l a c e m e n t du s y s t è m e d ' é c r i t u r e FAB
par
un équipement
plus
performant
rencontrant les nouveaux besoins des
a c t i v i t é s de l'INO.
«Nous
sommes
convaincus
que
le
système
offert
permettra au Cégep de réaliser plusieurs
nouvelles a c t i v i t é s pertinentes pour la
f o r m a t i o n des é t u d i a n t s » ,
a
affirmé
monsieur Paquet.
L'INO c o m p t e présentement à son emploi
v i n g t - c i n q t e c h n o l o g u e s , dont v i n g t sont
des diplômés en technologie physique du
Cégep de La Pocatière. «Nous s o m m e s
parmi
ceux
qui
connaissons,
et
reconnaissons, l'excellence des diplômés
en technologie physique du Cégep de La
Pocatière, et nous s o m m e s heureux de
pouvoir offrir un appareil qui contribuera de
manière tangible à la f o r m a t i o n des f u t u r s
t e c h n o l o g u e s » , a ajouté monsieur Paquet.
D'ailleurs l'INO prévoit procéder d ' i c i le
mois de mai prochain au r e c r u t e m e n t d ' a u
moins trois nouveaux t e c h n o l o g u e s en
physique parmi les finissants de c e t t e
année.
Rappelons que l ' I n s t i t u t national d ' o p t i q u e ,
qui emploie à son siège social de SainteFoy plus de cent t r e n t e personnes dont
quatre-vingt
scientifiques,
est
une
c o r p o r a t i o n privée sans but lucratif qui a
v u le jour en 1 9 8 5 . L'INO est l ' u n des
chefs de file international de la recherche
et du d é v e l o p p e m e n t en optique, et vise à
favoriser l'essor é c o n o m i q u e du pays en
assistant les entreprises dans leurs e f f o r t s
pour améliorer leur c o m p é t i t i v i t é .
61
THE PHYSICS OF DILUTE 2D ELECTRON AND HOLE SYSTEMS IN SI-BASED
HETEROSTRUCTURES
by
Marie D ' l o r i o
I n s t i t u t e for M i c r o s t r u c t u r a l Sciences, National
INTRODUCTION
Starting
w i t h the d i s c o v e r y
of
the
Q u a n t u m Hall Effect at the beginning of
the
1980's,
the
field
of
low
dimensionality
electron
systems
has
known
an
incredible
expansion.
In
semiconductors,
the c o n f i n e m e n t of
charge
carriers
in
two
or
fewer
d i m e n s i o n s provides added richness f r o m
b o t h the f u n d a m e n t a l and the applied
physics v i e w p o i n t . Solid s t a t e vocabulary
has expanded t o include the integer and
the f r a c t i o n a l
Quantum
Hall
Effects
(IQHE, FQHE), s k y r m i o n s ,
composite
fermions,
high
electron
mobility
t r a n s i s t o r s (HEMT), m o d u l a t i o n doped
field
effect
transistors
(MODFETs),
resonant tunneling diodes (RTD) etc. In
the q u a n t u m limit of l o w t e m p e r a t u r e and
finite m a g n e t i c field w h e r e the m o b i l i t y f j
and t h e m a g n e t i c field B are s u c h that
/vB> > 1, charge carriers c o n f i n e d at the
i n t e r f a c e b e t w e e n t w o s e m i c o n d u c t o r s or
between
a
semiconductor
and
an
insulator behave as a gas of noninteracting particles (electron gas), w h i l e ,
in the e x t r e m e q u a n t u m limit w h e r e the
c y c l o t r o n energy h(oc is m u c h larger than
t h e t h e r m a l energy k^T, the f l u c t u a t i o n s
p r o m o t e the f o r m a t i o n of a liquid state. It
w a s natural t h e n t o look for the third
s t a t e of m a t t e r , the solid in t w o dimensions. This idea w a s not n e w , as it had
been addressed by Eugene W i g n e r in
1 9 3 4 [1] for three dimensional metallic
s y s t e m s . W i g n e r predicted t h a t , at zero
magnetic field, t h e d e n s i t y of the carriers
could be reduced such t h a t the C o u l o m b
exchange w o u l d be larger t h a n the
t h e r m a l disordering energy, t h u s f a v o r i n g
the c r y s t a l l i z a t i o n
of
electrons
onto
lattice sites. This w a s later applied t o t h e
two-dimensional
case
where
the
c o n d i t i o n s for observing the e l e c t r o n
solid are less stringent t h a n in three
dimensions |2,3|.
BACKGROUND
There are t w o regimes for the f o r m a t i o n
of a solid phase depending on w h e t h e r
the c o m p e t i n g f l u c t u a t i o n s are t h e r m a l or
q u a n t u m in nature.
= tf / ( m * a 2 ) < <
W h e n r is large, the f o r m a t i o n of a solid
is f a v o r e d over that of the
liquid.
Electrons on a helium f i l m provided the
first o b s e r v a t i o n of a classical W i g n e r
solid at zero magnetic field and the
m e l t i n g t e m p e r a t u r e w a s f o u n d t o occur
at T m = l/ c /(TM
w i t h rm =
127±3
[4-8!.
(b) The q u a n t u m regime occurs at l o w
t e m p e r a t u r e s w h e n T < < TF and the
parameter of interest is the ratio of the
Wigner-Seitz radius, a t o the Bohr radius
a8:
r, = a/a B=
62
Vc/(kaT)
Physics in Canada
Vc/(kBTh)
and
aB=
tfe
/(o*m
*)
The electrons order into a W i g n e r c r y s t a l
when
r 3 is large and the
Coulomb
correlations d o m i n a t e ; as the carrier
d e n s i t y increases and r, decreases the
q u a n t u m f l u c t u a t i o n s g r o w until the long
range
order disappears and the solid
m e l t s . This occurs at a critical value r,"
= 37± 5 or critical d e n s i t y rT = n /(r,w
ag)2 as d e t e r m i n e d by a finite size, zero
t e m p e r a t u r e calculation | 9 ] .
(c) It is also possible t o induce the
crystallization of electrons by applying a
magnetic field perpendicular t o the layer
and localizing the electrons w i t h i n a
magnetic length lc = (hc/eB)h,
smaller
t h a n the Wigner-Seitz radius a . The
q u a n t u m f l u c t u a t i o n s are quenched and
there
is little overlap b e t w e e n
the
e l e c t r o n w a v e f u n c t i o n s . The ratio of the
zero point energy t o the magnetic or
c y c l o t r o n energy ha>c w h e r e coc =
eB/m'c
is provided by the filling f a c t o r v =
i
2(lc/a)'
.
The
magnetically
induced
W i g n e r solid is expected to form at finite
t e m p e r a t u r e at a filling f a c t o r smaller
t h a n some critical value vc w h i c h has
been e s t i m a t e d t o be b e t w e e n 1/3 and
1 / 1 1 . The phase diagram is illustrated in
Fig. 1.
n.
kBT
w h e r e a = Inn,) * is t h e radius of the
Wigner-Seitz cell, n, is the carrier d e n s i t y ,
Tf is the Fermi t e m p e r a t u r e and m* is t h e
e f f e c t i v e mass. The parameter of interest
is the
ratio
between
the
Coulomb
correlation
energy
and
the
thermal
disordering energy. This is expressed as:
T =
O t t a w a , Ontario
w h e r e Vc ~ e?/z a and e is the dielectric
constant.
(a) In the classical regime, the zero point
energy is m u c h smaller t h a n the t h e r m a l
energy k B T:
kBTF
Research Council of Canada,
M arch/Aprill 9 9 6
Fig. 1
The phase diagram for the classical
and quantum Wigner solid indicating
the classical melting temperature, the
critical melting density and critical
magnetic field.
K1A OR6
Experimentally, the problem lies in the
f a c t t h a t the carrier d e n s i t y required for
observing the q u a n t u m solid phase is
very l o w in lll-V s e m i c o n d u c t o r s w h i c h
t y p i c a l l y have l o w e f f e c t i v e masses and
large dielectric c o n s t a n t s : r „ ~ 2 - 4 < < r, w .
Electrons on helium have the opposite
problem w h e r e the d e n s i t y is kept l o w t o
avoid a d e s t r u c t i v e instability of t h e
helium surface: r, à 10 3 > > r, w . The
search should thus f o c u s on material
s y s t e m s w i t h a large e f f e c t i v e mass, a
l o w dielectric c o n s t a n t , and in situ
d e n s i t y t u n a b i l i t y . W e should also search
for other material features w h i c h f a v o r
the onset of crystallization. This is the
approach that w e w i l l be discussing.
W h a t are the signatures for the f o r m a t i o n
of the W i g n e r solid phase? J u s t like its
liquid c o u n t e r p a r t , the electron solid is a
collective phase; this is in c o n t r a s t t o t h e
gas phase w h e r e the picture of a noninteracting gas usually s u f f i c e s . The
solid, h o w e v e r , should have
rigidity
w h i c h w i l l d i s t i n g u i s h it f r o m a collective
liquid state.
From
magneto-transport
e x p e r i m e n t s , one w o u l d expect s o m e
e x t r e m e l y large resistance
associated
w i t h the localization of the
charge
carriers o n t o lattice sites and their
inability t o participate in the t r a n s p o r t .
But that in itself is not s u f f i c i e n t since
single-particle localization w i l l also lead t o
insulating behavior. The current-voltage
characteristics could h o w e v e r
provide
unambiguous evidence for a solid phase.
The
presence
of
an
electric
field
threshold c o n d u c t i o n is indicative of
rigidity: b e l o w threshold, the electrons
are pinned w h i c h is not possible in a
liquid phase, w h i l e , above threshold, a
collective sliding m o t i o n of the depinned
electron solid occurs. The resistance
b e l o w threshold is usually activated due
t o electrons e x c i t e d across a "singlee l e c t r o n " disorder
induced gap. The
c o n d u c t i o n here can involve t h e transport
of electrons along the grain boundaries of
the W i g n e r solid or the transport of
dislocation
pairs.
A
low
value
of
threshold field implies a long correlation
length w i t h respect t o the Wigner-Seitz
radius. A n o t h e r signature of the W i g n e r
solid is the increase of broadband noise
as the threshold field is approached; t h i s
corresponds t o the onset of sliding and
the noise generated by t h e e l e c t r o n
lattice sliding by the pinning centers.
There also should be a t e m p e r a t u r e
above w h i c h the thermal disordering
energy takes over and the solid " m e l t s "
as w e l l as a critical carrier d e n s i t y above
w h i c h the zero point oscillation energy
overtakes the C o u l o m b interaction | 1 0 ) .
The w o r k on the f o r m a t i o n of the
classical W i g n e r c r y s t a l using electrons
on a t h i n helium f i l m set the stage for
e f f o r t s in s e m i c o n d u c t o r s . The substrate
under the
helium f i l m
can
provide
s u f f i c i e n t surface roughness t o pin the
W i g n e r c r y s t a l f o r m e d by the electrons.
A s s o c i a t e d w i t h this pinning are nonlinear c u r r e n t - v o l t a g e (/-I/) c h a r a c t e r i s t i c s
w h i c h w e r e first observed by Kajita 111).
A b o v e a threshold electric field, the
depinned c r y s t a l slides like a sliding
charge d e n s i t y w a v e . Experiments o n a
two-dimensional
sheet
of
electrons
injected on a helium f i l m (thickness 2 0 0 4 0 0 A), supported by a glass s u b s t r a t e ,
have s h o w n t h a t the t r a n s p o r t properties
of the pinned e l e c t r o n lattice are v e r y
similar t o that of one-dimensional sliding
charge d e n s i t y w a v e s : c h a r a c t e r i s t i c nonlinear l-V c u r v e s , m e l t i n g t e m p e r a t u r e ,
and broadband noise g e n e r a t i o n | 1 2 | .
The initial e f f o r t in i d e n t i f y i n g a W i g n e r
c r y s t a l phase in s e m i c o n d u c t o r s
was
carried
out
in
GaAs/AIGaAs
heterostructures [13-151. There, it w a s
not possible t o decrease the d e n s i t y
s u f f i c i e n t l y t o observe the W i g n e r c r y s t a l
at
zero
magnetic
field.
Thus
the
e x p e r i m e n t a l e f f o r t s w e r e f o c u s e d on the
magnetic field induced W i g n e r c r y s t a l in
the f r a c t i o n a l q u a n t u m Hall regime. At
l o w fields, the q u a n t u m
fluctuations
d o m i n a t e the C o u l o m b correlations and
the Integer Q u a n t u m Hall Effect ( w h e r e
P*y = h/ve 2 and p x x —>0, v is an integer) is
o b s e r v e d w h e n w e a k disorder pins the
Fermi level in the gap b e t w e e n Landau
levels. A s the field is increased f u r t h e r ,
the electrons behave as a correlated
quantum
liquid
which
exhibits
the
Fractional Q u a n t u m Hall Effect ( w h e r e p x v
2
= h/ve and v = p/q and p and q are
integers and q is odd). A t e x t b o o k
e x a m p l e of these phenomena is s h o w n in
Fig. 2. Transitions t o an e l e c t r o n solid
phase are possible depending on w h i c h
phase has the l o w e s t g r o u n d
state
energy. Compelling evidence for the
m a g n e t i c field induced W i g n e r solid have
been
provided
by
electrical,
radiof r e q u e n c y and optical m a g n e t o - t r a n s p o r t
e x p e r i m e n t s near filling f a c t o r 1/5, 2 / 7 in
n-type
GaAs/AIGaAs
heterostructures
and 1/3 in similar p - t y p e samples [16J.
In order t o observe a q u a n t u m W i g n e r
c r y s t a l , in the zero field limit predicted by
W i g n e r , one must look for a material
s y s t e m w i t h large e f f e c t i v e mass to
minimize the zero point oscillation energy
and
a small
dielectric
constant
to
maximize
the
Coulomb
correlation
energy. M o r e o v e r , it is i m p o r t a n t to be
able t o vary the d e n s i t y in a reliable and
reproducible
fashion.
Almost
optimal
conditions can be created in several Sibased materials as s h o w n in Table 1.
5 x 1 0 ' ° t o 10 12 c m 2 . The longitudinal
resistance is measured using a four probe
technique w i t h a d i f f e r e n t i a l e l e c t r o m e t e r
and DC currents as l o w as 0 . 1 pA. The
Oxford
Instrument
low
temperature
s y s t e m consists of a t o p loading 4 0 0 /vW
dilution refrigerator (25 mK < T < 4 . 2
K) and a s u p e r c o n d u c t i n g magnet (H 0 - 1 5 Tesla @ 4 . 2 K). One of the main
d i f f e r e n c e s b e t w e e n Si-MOSFETs and
GaAs/AIGaAs
modulation
doped
h e t e r o j u n c t i o n s is the location of the
d o p a n t s
w h i c h
control
the
scattering
Parameter
Si/SiGe
Si/Si02
events
and
hence
limit
Electron effective mass :
0.44
0.19
the m o b i l i t y .
m'
I n
S i Dielectric constant :
MOSFETs
12
7.7
the d o p a n t s
<K>
are
located
Bohr radius :
in
the
Si
close t o the
_
(4 ne.X» 2 *)
14 A
20 A
B
. ,
inversion
m e
layer.
The
Interelectron spacing :
scattering is
short
range
1
126 A
182 A
in this case.
V^nT
In c o n t r a s t ,
@ n s = 2 x 1 0 1 1 cm" 2
@ n s = 9.6 x 1 0 1 0 cm" 2
the
lll-V
heterostruct
Wigner-Seitz radius :
ures
have
a
d o p a n t s
9
9
"B
separated
from
the
Critical concentration for
t
w
o
quantum cold melting :
dimensional
1
( 0 . 9 2 - 1.59) x 10 1 0
(0.43 - 0.70) x 10 1 0
layer by a
spacer layer
cm" 2
cm" 2
and
the
where rc = 37 ± 5
scattering is
long range.
Other t h a n the physical parameters of the
Table 2 s h o w s a c o m p a r i s o n of these
material, it is possible t o choose a
samples w i t h those used in the s t u d y of
s y s t e m w h i c h , by its epitaxial layered
magnetic field induced W i g n e r c r y s t a l
g r o w t h , can enhance the f o r m a t i o n of
f r o m the point of v i e w of "inherent
the W i g n e r c r y s t a l . It is k n o w n that the
disorder".
coupling b e t w e e n t w o electron s y s t e m s
separated by less t h a n the interelectron
Table 2
distance f a v o r s W i g n e r
crystallization
Relative Disorder in V e r y H i g h M o b i l i t y
117-181. Here, w e w i l l look at t w o
Si MOSFETs and G a A s - A I G a A s
s y s t e m s : Si-Si0 2 field e f f e c t transistors
Heterostructures
or
Si M O S F E T s
(metal
oxide
Si-MOSFETs
GaAs-AIGaAs
s e m i c o n d u c t o r field e f f e c t transistor) and
2
p - t y p e Si-SiGe-Si heterostructures.
10' 2
n; (cm'
(cm )
l-3x[0'°
1-3x10'°
Table 1. Comparison of parameters of interest for Wigner crystallisation
SAMPLES
B ïhGJ
Fig. 2
Textbook example of the Integer and
Fractional Quantum Hall Effects. From
A. Chang,
The Quantum
Hall
Effect,
ed. R. E. Prange and S. M. nd
Girvin,
Springer-Verlag, New York, 2
Ed.
(1990).
A number of Si-MOSFETs g r o w n in
Russia w e r e studied in detail.
The
e l e c t r o n m o b i l i t y in these samples is an
order of magnitude larger than t h a t of
c o m m e r c i a l Si-MOSFETs and 2 - 4 t i m e s
larger t h a n t h a t of the best Si-MOSFETs
grown
for
research
purposes.
This
mobility
was
achieved
by
careful
processing to avoid highly
diffusive
c o n t a m i n a n t s such as Na and K ions, and
repeated g r o w t h and stripping of the
thermal
oxide t o
ensure a
smooth
interface. The samples have the f o l l o w i n g
l o w t e m p e r a t u r e peak mobilities: Si-15: y
= 7.1 x 10" c m 2 / V s , Si-5: /y = 4 . 3 x 1 0 4
c m ' / V s , Si-1 1 : /J = 3 . 6 3 x 1 0 " c m 2 / V s ,
and Si 2: /v = 2 . 4 2 x 10 4 c m 2 / V s . By
applying a bias to the AI t o p gate, the
carrier d e n s i t y can
be varied
from
0.1-0.3
10-15
setback distance d
50-100 A
-500 A
setback/Bohr radius:
d/a B
2.5-5
5
ni / n ,
In the dilute
limit,
where
impurity
scattering d o m i n a t e s , the Si-MOSFETs
and the G a A s / A I G a A s are equivalent
systems.
RESULTS
In probing the dilute d e n s i t y
regime
below
1x10"
cm2,
a number
of
anomalous features w e r e discovered in
the m a g n e t o - t r a n s p o r t m e a s u r e m e n t s at
half-filled Landau levels (v = 5 / 2 , 3 / 2 ) .
La Physique au Canada mars à avril 1 9 9 6
63
Some of these are shown in Fig. 3:
6
2.5
2
1 2
3
4
Magnetic f i e l d (T)
Fig. 3
•
•
•
•
The longitudinal and Hall resistances
as a function of magnetic field for
sample Si-5 at 2 carrier density n. =
9.33 x 1 0 ' ° c m .
Instead of regular Shubnikov-de Haas
oscillations obtained from measuring
the resistance along the sample as a
function of magnetic field, the maxima
in the Shubnikov-de Haas oscillation at
half-filled
Landau
levels
become
enormous w i t h resistances ~ 1O'2 ohms
depending on the carrier density. The
resistance goes back d o w n to the level
of a f e w ohms as the magnetic field is
swept into the quantum Hall minima at
filling factors v = 2 and 1.
If the magnetic field is kept at one of
the SdH oscillation maxima, and the
current-voltage (l-V) characteristics are
measured at constant density, the
result is a sharp non-linear l-V curve
w i t h a low threshold field value which
increases as the carrier density is
decreased:
The resistance at the SdH maxima is
thermally activated below threshold
w i t h p xx <*
The activation energy
increases linearly w i t h
decreasing
density.
Because the Fermi energy is comparable
to these splittings, polarization effects
will be important. While the ground state
energetics of the liquid phase is sensitive
to the polarization state, the solid phase
is relatively unaffected by polarization
due to the weaker exchange energy.
Whereas the Monte Carlo simulation for a
pure system suggests that the transition
to the Wigner crystal should occur at r,
= 37 |9[, a fixed node and variational
Monte Carlo simulation incorporating the
valley degeneracy and impurity effects in
Si-MOSFETs yield a partially polarized
fluid to a fully polarized solid transition at
r, = 7.5 (211! It should be possible then
to observe the quantum Wigner crystal at
zero magnetic field in very high mobility
Si-MOSFETs!
Theoretically, there is little doubt that,
for zero disorder and zero temperature,
the 2D electron gas will crystallize into a
Wigner lattice upon lowering the density.
It is also accepted that, in the limit of
strong
disorder,
single-particle
localization will set in. Our samples w i t h
minimal disorder provide an intermediate
regime where a collective insulating state
like the pinned Wigner solid |22| or the
pinned charge density wave [23] might
exist. The study of the zero field
longitudinal resistance as a function of
carrier density and temperature led to the
following experimental observations:
•
Below a critical carrier density n,,. ~ 1 0 "
cm2,
the
longitudinal
resistivity
exhibits
insulating
behavior
characterized by an exponential rise
shown in Fig. 4(a) and a negative
slope in the temperature dependence
dR„/3T.
1.0
<
0.5
0.0
Fig. 4(b) The carrier density dependence of
the activation energy and the
threshold electric field for sample
Si-2. The 10
critical density is
=
10.05 x 10 cm 2 .
15
?
I
£
f
(a)
f
5
J
-5
-15
-1.0
-0.5
T=35mK
n.=8.32
0.0
0.5
C u r r e n t (nA)
1.0
Fig. 5(a) The current-voltage characteristics
at carrier
density n, = 8 . 3 2 x 1 0 ' °
cm 2 and zero magnetic field for
sample Si-2.
-0.5
0.0
0.5
C u r r e n t (nA)
1.0
Fig. 5(b) The broadband noise voltage
measured between
potential
contacts as a function of the
source-drain current.
While
the
large
resistance
is
developing along the sample, the Hall
resistance across the sample remains
metallic as it does in the high density
regime.
These surprising observations (191 led us
to believe that the two-dimensional
electron gas was undergoing a series of
re-entrant transitions from an insulating
state characteristic of some new phase
to the non-interacting gas of the integer
quantum Hall regime. In view of the
results attributed to a magnetic field
induced Wigner crystal near filling factor
1/5 in GaAs/AIGaAs heterostructures, we
looked into the conditions required for
Wigner crystallization in Si-MOSFETs and
found them to be quite favorable in
theory. The large effective mass m * =
0 . 1 9 m 0 and the low dielectric constant
E = 7.7
set Si-MOSFETs apart from
GaAs-AIGaAs
heterostructures;
in
addition, Si-MOSFETs feature a two-fold
64
valley degeneracy which is lifted by
intervalley
interaction
and
the
asymmetric confinement potential (Av =
2 . 4 K), and a large spin splitting w h i c h
persists d o w n to zero field (As = 4 K) due
to the large spin-orbit coupling [201.
Physics in Canada M arch/Aprill 996
7.5
10.0
n , (1010cm~2)
12.5
Fig. 4(a) The longitudinal resistivity as a
function of carrier density for
sample Si-2 at zero magnetic field.
In the temperature range 100-650 mK,
the temperature dependence of R„K can
be described by R„x
e " 7 where the
activation energy A drops linearly to
zero at n8C as shown in Fig. 4(b).
5
6
7
8
Frequency (kHz)
9
Fig. 5(c) T w o i n d e p e n d e n t
spectral
measurements of the narrowband
noise driven by the DC current.
The
current-voltage
characteristics
exhibit a sharp d r o p in 3V/9I above a
threshold electric field E, as s h o w n in
Fig. 5(a).
The threshold field goes t o
zero
s m o o t h l y at n sc as s h o w n in Fig. 4(b).
The data can be f i t t e d w e l l by a p o w e r
l a w E,
Ônsr w h e r e y =
1.7-1.8
and ôn s = (n sc -n„) (see Fig. 6). More
accurate m e a s u r e m e n t s have actually
revealed a small d i s c o n t i n u i t y at n sc
pointing to a first order t r a n s i t i o n [ 2 4 | .
The dependencies of the a c t i v a t i o n
energy and the t h r e s h o l d field on
carrier d e n s i t y is sample independent.
H o w e v e r , t h e critical carrier d e n s i t y is
lower
for
higher
mobility
(less
disordered) samples.
The
sharp
rise
in c o n d u c t i o n
is
a c c o m p a n i e d by a steep increase of
the
broadband
rms-noise
voltage
(V N ) as a f u n c t i o n of current (see
Fig. 5(b)). The broadband noise w a s
measured at t w o nearest potential
c o n t a c t s in the 1 - 3 0 0 kHz f r e q u e n c y
band.
The n a r r o w b a n d noise s h o w n in Fig.
5(c) has a reproducible
frequency
spectrum
which
shifts
to
higher
f r e q u e n c y as the d r i v i n g current is
increased. The m a x i m a in the signal
a m p l i t u d e occur at frequencies w h i c h
can be r e l a t e d t o the 2D electron
lattice c o n s t a n t s .
100
dn 3 (10 c m " )
Fig. 6
The dependence of the threshold
electric field on the carrier density
variation n„-n, for sample Si-2.
The
solid line is a fit to Et = 8n„1 8 while
the dashed line is the theoretical
dependence E, = 8n,'
These
zero m a g n e t i c
field
transport
signatures are similar t o those observed in
the classical W i g n e r solid of electrons on
helium and the m a g n e t i c - f i e l d induced
W i g n e r solid near fractional filling f a c t o r
1/5. In the very high m o b i l i t y samples,
these features are also seen at filling
f a c t o r s 3 / 2 and 5 / 2 at m a g n e t i c fields
b e l o w 5 Tesla. But let us f o r g e t this for a
m o m e n t and play d e v i l ' s a d v o c a t e . Could
this be s i m p l y a m a n i f e s t a t i o n of singleparticle localization (SPL)? In disordered
semiconductors
at
low
temperature,
transport takes place by means
of
phonon-assisted tunneling to states w h i c h
are close in energy. The
tunneling
d i s t a n c e t o a state w i t h i n k„T of the Fermi
energy
increases
with
decreasing
t e m p e r a t u r e . This variable range hopping
process has a characteristic p o w e r law
dependence of the r e s i s t i v i t y on the
t e m p e r a t u r e : p(T) = p 0 exp(T 0 /T)" w h e r e x
= 1/3 for single particle localization in 2D
without
Coulomb
interaction
[25].
Experimentally, w e cannot fit our data t o
variable range hopping but observe an
a c t i v a t e d t e m p e r a t u r e dependence w i t h x
=
1; more recent results, in similar
samples, have provided evidence for a
C o u l o m b gap ( x = 1 / 2 ) in the d e n s i t y of
states at the Fermi energy, in an
intermediate t e m p e r a t u r e range ( 2 6 | . In
SPL,
the
threshold
conduction
is
associated
w i t h the
breakdown
of
localized states w h e n eE,^ 0 ( w h e r e E, is
the threshold and );0 is the localization
length) is comparable t o the Fermi energy
E ( . For the l o w
threshold field at
ôn s = 0 . 1 x 1 0 ' ° c m 2 and EF = 6 K, the
localization length w o u l d have t o be
longer than the sample itself i.e.
= 6
m m . The threshold field typical of SPL is
of order 2 . 9 x 1 0 3 V / c m [271 for our
e x p e r i m e n t a l conditions. Our threshold
fields are f i v e orders of
magnitude
smaller.
A
series
of
capacitance
m e a s u r e m e n t s on these samples also
show
that
the
effective
area
for
c o n d u c t i o n does not change as the carrier
density
is d e c r e a s e d
[28[.
Our
e x p e r i m e n t a l results are therefore not
consistent
with
s i ng I e - pa r t i c I e
localization.
However,
single-particle
localization
is
expected
to
become
d o m i n a n t in t h e regime w h e r e the number
of carriers has been decreased so m u c h
that it is equal t o the number of pinning
impurities in the oxide layer. The more
rapid increase of the threshold field below
7 . 5 x 1 0 ' ° c m 2 is a precursor of this
phase.
Let
us
consider
the
data
in
the
f r a m e w o r k of a pinned W i g n e r c r y s t a l . By
d r a w i n g an analogy t o a charge d e n s i t y
w a v e ( C D W ) , it m a y be easier t o
understand
the
experimental
results.
Charge d e n s i t y w a v e s are predominantly
a one-dimensional p h e n o m e n o n although
t h e y also occur in materials w i t h t w o or
three-dimensional band s t r u c t u r e s [ 2 9 | .
Chain and layer s t r u c t u r e s in w h i c h C D W
t r a n s i t i o n s have been studied include
organic c o n d u c t o r s such as TTF-TCNQ
(tetracyanoquinodimethane)
and
linear
chain inorganic materials such as TaS 3 ,
NbSe 3 and blue bronze K 0 3 M o O 3 . In these
materials, the electron d e n s i t y is spatially
dependent consisting of the unperturbed
electron d e n s i t y
in the absence
of
e l e c t r o n - p h o n o n interaction g i v e n by p0
= K/kf in one-dimension, and a collective
mode formed
by electron-hole
pairs
i n v o l v i n g t h e w a v e v e c t o r q = 2kr :
p(/) = p0+ p,cos(2klr+
<P)
w h e r e kF is the Fermi w a v e v e c t o r and <Z>
is the phase. The collective mode results
f r o m the pairing of electron and holes on
either side of the Fermi suface t o f o r m a
condensate called a charge d e n s i t y w a v e
and an a c c o m p a n y i n g lattice d i s t o r t i o n .
A s in s u p e r c o n d u c t i v i t y , there is a gap in
the single-particle e x c i t a t i o n s p e c t r u m , a
collective mode described by a c o m p l e x
order parameter, and a phase w h o s e t i m e
and spatial d e r i v a t i v e s are linked t o
electric current and condensate d e n s i t y .
Both amplitude and phase f l u c t u a t i o n s
can occur but w h e r e a s the amplitude
m o d e has a gap, the phase e x c i t a t i o n s
are gapless. Pinning is a central concept
in C D W physics as the translational
symmetry
is broken by
electrostatic
potentials caused by impurities and grain
boundaries w h i c h serve t o pin the
collective mode. The C D W s y s t e m s are
c o m p o s e d of normal electrons c o e x i s t i n g
w i t h a condensate and scattering w i t h
the
normal
electrons
reduce
the
coherence length. A m o n g the transport
properties associated w i t h the d y n a m i c s
of the collective mode are (1) non-linear
electrical c o n d u c t i o n w i t h a threshold
electric field, (2) a metal-insulator or a
m e t a l - s e m i c o n d u c t o r t r a n s i t i o n below a
distinct
melting
temperature
accompanied
by
a
periodic
lattice
distortion
incommensurate
with
the
underlying
lattice,
(3)
anomalous
m i c r o w a v e c o n d u c t i v i t y , (4) dc and ac
e x c i t a t i o n s d o m i n a t e d by the collective
mode d y n a m i c s , and (5) s t r o n g f r e q u e n c y
dependent response in a broad f r e q u e n c y
range. In s t u d y i n g s u c h s y s t e m s it is
essential t o examine intrinsic d e f e c t s due
to
thermal
fluctuations
as w e l l
as
defects,
vacancies
and
dislocations
induced by q u a n t u m f l u c t u a t i o n s as t h e y
are believed t o play an i m p o r t a n t role in
the melting transition.
W h a t drives the c o n d u c t i o n in the C D W ?
Let us imagine t h a t a C D W is pinned by
the electrostatic potential w e l l of an
i m p u r i t y . If an external electric field is
applied, the C D W d e f o r m s around the
pinning center
but
electrons
remain
constrained by the phase coherent C D W .
The electrons w h i c h have not condensed
in a C D W
can
still c o n t r i b u t e
to
c o n d u c t i o n by thermal a c t i v a t i o n across
the gap but because of their l o w d e n s i t y
the r e s i s t i v i t y of the pinned C D W is high.
At l o w t e m p e r a t u r e s w h e n all electrons
have frozen out, the a c t i v a t i o n energy is
related t o the energy required t o change
the phase of the local C D W in a coherent
d o m a i n by 2jc. A b o v e a critical threshold
field, the entire C D W
can
become
depinned and slide c o h e r e n t l y in the
d i r e c t i o n opposite t o that of the applied
electric field. The d i f f e r e n t i a l resistivity
drops sharply giving rise t o sharp nonlinear l-V characteristics. The larger the
number of pinning impurities, the greater
the loss of phase coherence and the
s m o o t h e r the l-V c h a r a c t e r i s t i c s . A s the
C D W slides past s t a t i o n a r y
impurity
potentials, the voltage noise generated
by the perturbation of the
impurity
potential w i l l depend on the current, the
carrier d e n s i t y and the period of the
C D W . The size of the phase coherent
d o m a i n s is defined by the correlation
length w h i c h can be measured f r o m the
transverse shear modulus, the threshold
field, the interelectron spacing, and the
carrier density.
65
In analogy t o C D W s y s t e m s , the electron
solid f o r m s
in the
presence
of
a
neutralizing b a c k g r o u n d charge w h i c h
f i x e s the d e n s i t y w h e n the potential
energy b e t w e e n t h e localized electrons
d o m i n a t e s all other energies in the
problem. In m o s t samples, the solid
phase
coexists
with
uncrystallized
electrons. H o w e v e r , the phase coherence
length remains large c o m p a r e d t o the
interelectron spacing in the e l e c t r o n solid
( i n G a A s : 4 . 8 / v m > > 1 0 0 r , ~ 3 0 0 Â ) . Thus
q u a n t u m depinning and d e f e c t w a v e s or
d i s l o c a t i o n pairs are possible in electron
s y s t e m s but unlikely in C D W . The t y p e of
pinning, w e a k or strong, w i l l depend on
t h e location, nature (acceptor or donor),
and number of pinning impurities. A
s u c c e s s f u l m o d e l for t h e
conduction
m e c h a n i s m in the W i g n e r solid has been
developed by Chui. The model assumes
t h a t the charge c a r r y i n g e x c i t a t i o n s are
bound
dislocation
pairs.
A
single
d i s l o c a t i o n can be visualized as a shift of
the electrons f r o m equilibrium position
which
can
be
described
by
a
d i s p l a c e m e n t field. A d i s l o c a t i o n pair
consists
of
two
dislocations
with
d i s p l a c e m e n t fields in opposite d i r e c t i o n s ;
there is a net d i s p l a c e m e n t of charge
b e t w e e n the dislocations and the m o t i o n
of this locally altered d e n s i t y is possible
with
resulting
conduction.
This
is
equivalent t o the phase slip model in
CDW.
If w e r e v i e w the e x p e r i m e n t a l results, the
similarities b e t w e e n the pinned charge
d e n s i t y w a v e and the pinned e l e c t r o n
solid are striking. There is a critical
d e n s i t y and a critical t e m p e r a t u r e b e l o w
w h i c h the insulating phase appears. The
t r a n s i t i o n at the critical carrier d e n s i t y is
w e a k l y first order in character. The nonlinear
l-V
characteristics
can
be
interpreted as s h o w i n g that at small
c u r r e n t s the W i g n e r c r y s t a l is pinned by
the
neighboring
impurities
until
the
threshold field is exceeded and the
W i g n e r c r y s t a l slides. Over the range of
densities 7 . 2 x 1 0 ' ° - 1 . O x 1 0 " c m 2 the
threshold field decreases as E,oc(nc-ns)p
w h e r e P = 1 . 7 - 1 . 8 . This is in agreement
w i t h a depinning m e c h a n i s m involving
the c r e a t i o n and separation of d i s l o c a t i o n
pairs 130|. The theoretical model agrees
w e l l w i t h the e x p e r i m e n t a l results as
s h o w n in Fig. 6. The f a c t t h a t the subt h r e s h o l d a c t i v a t i o n energy b e l o w 1 0 0
mK is m u c h smaller t h a n that above is
consistent
with
extended
defect
c o n d u c t i o n 131). If one ignores q u a n t u m
coherence
effects,
the
motion
of
extended d e f e c t s and in particular that of
d i s l o c a t i o n pairs is equivalent t o phase
slippage in a charge d e n s i t y w a v e 132|.
The o%% versus electric field curves can be
f i t t e d t o a phase slippage equation of the
type:
o„=
{l 0 /4E)e' A / k T ) sinh [neE/A / k T |
w h e r e /„ is t h e intercontact distance, l 0 is
related t o the current created by a single
phase slip and /, is a characteristic phase
slip length. T h e value of /, obtained f r o m
the fit in Fig. 7 is 0 . 2 3 /ym, or t e n t i m e s
the interelectron spacing.
66
Physics in Canada
M arch/Aprill 9 9 6
frequency s h i f t s w i t h current, there is no
simple relation that can be applied t o link
the results t o a hexagonal or triangular
lattice s y m m e t r y . It is likely that part of
the current is provided by " u n c o n d e n s e d "
electrons hopping beyond the lattice.
10
Si-5
n,=6.69
3
•U
r ' = 6.7K"
C
o
o
TT
10
0.0
2.0
4.0
Electric
Fig. 7
6.0
Field
8.0
10.0
(V/cm)
Conductivity versus applied electric
field for sample
Si-5 at n. =
6.69 x 10'° cm 2 . The solid lines are a
single fit to the data at both
temperatures using phase slip model.
W h a t i n f o r m a t i o n can w e get about the
collective transport of depinned domains
above the threshold field? By using the
approach of elastic theory 133) as applied
t o charge d e n s i t y w a v e s in the w e a k
pinning limit, w e can e s t i m a t e
the
correlation length or d o m a i n size, L 0 as
{Kra/(2ne n,E,))*
where
KT
is
the
transverse shear modulus, and a is the
interelectron spacing. The experimental
dependence of the threshold field on the
carrier d e n s i t y s h o w s that the correlation
length diverges as ( ô n , ) 0 9 and thus L D
becomes smaller as the d e n s i t y
is
decreased, driving the s y s t e m t o w a r d s
single-particle localization. Single-particle
localization does have " i t s place in the
s u n " in the phase d i a g r a m .
The a c t i v a t i o n energy and the threshold
field can be used t o e x t r a c t
some
characteristic
length
scale
for
the
electron
solid,
e.g.
the
elementary
crystallite size of the pinned Wigner solid.
For a carrier d e n s i t y n, = 8 . 4 x 1 0 ' ° c m 2 ,
the sample t y p i c a l l y consists of pinned
crystallites a p p r o x i m a t e l y 0 . 7 ^ m x 0 . 7
fjm in size each containing about 3 0 0
electrons w i t h an interelectron distance ~
4 0 0 Â!
The generated broadband noise s h o w n in
Fig. 5(b) is also consistent w i t h depinning
of the Wigner c r y s t a l or coherent defect
m o t i o n above threshold. T h e n a r r o w b a n d
noise
should
yield f r e q u e n c y
peaks
related t o the principal lattice spacings. If
w e assume that the electron lattice
e x t e n d s across the entire 2D layer of
w i d t h w and that t h e t o t a l current I is
only provided by the sliding lattice, the
spectral m a x i m a w i l l be related t o the
principal lattice spacing ri, as t^
=
l / f e n , ! ^ ) . For a hexagonal lattice sliding
in a r a n d o m field of point d e f e c t s , r|, =
b, i) 2 = -v3 b, and r| 3 = 2 b w h e r e b is
the distance b e t w e e n nearest neighbor
electrons. Experimentalists have been
urged t o t r y this e x t r e m e l y
difficult
m e a s u r e m e n t as it could provide the
definitive signature for lattice ordering of
electrons- the " s m o k i n g g u n " for W i g n e r
crystallization. A l t h o u g h there are peaks
in the n a r r o w b a n d s p e c t r u m and the
Peak m o b i l i t y ( c m / V s )
Fig. 8
Phase
diagram
for
the
twodimensional electron system showing
the critical density versus the sample
peak mobility.
By s t u d y i n g samples in a w i d e range of
mobilities and carrier densities, w e have
been able t o
probe the e f f e c t
of
" d i s o r d e r " on the d e v e l o p m e n t of the
insulating phase. Fig. 8 s h o w s the phase
diagram
for
the
formation
of
the
collective insulator phase or q u a n t u m
Wigner
solid
confined
between
the
metallic state above the cold m e l t i n g
boundary n c m (full line) and the A n d e r s o n
insulator or the regime of single-particle
localization b e l o w the n sill boundary. By
using a calculation by Gold 1341 for t h e
m o b i l i t y of Si(100) inversion layers, w e
obtain a s a t i s f a c t o r y model for the peak
mobility versus carrier d e n s i t y in our
samples. The number of impurities n: is a
better
indicator
of disorder
as
the
impurities
are the
main
source
of
scattering
at
low
densities
(below
2
2 x 1 0 " c m ) . The boundary for SPL is
estimated f r o m n, and depicted by a short
dashed line. This is the highest e s t i m a t e
for SPL in our samples w h e r e the surface
roughness is m u c h l o w e r t h a n that used
t o calculate n, and nSPL. The full triangles
indicate nsn
estimates if the d o m a i n
length Ln is t w i c e the
interelectron
distance L0 = 2a. The solid line is the
calculated
dependence
of
the
cold
melting d e n s i t y on
using the mean
square displacement as a f u n c t i o n of ni
and an estimate of the cold m e l t i n g
density
as
nt goes
to
zero.
The
calculation of the t r a n s i t i o n f r o m a
polarized W S t o a partially polarized liquid
at r s - 10 (n„ ~ 7 . 6 5 x 1 0 ' ° c m 2 ) is
represented by a bar 1211 and is in
agreement w i t h the data for Si-5 and Si11. This phase diagram also explains
w h y such a collective phase w a s not
observed by other g r o u p s using l o w e r
m o b i l i t y samples and suggests that w e
should be looking for a material s y s t e m
w i t h as g o o d if not better material
parameters t h a n the high m o b i l i t y SiMOSFETs studied here. Thus there is
m o u n t i n g e x p e r i m e n t a l evidence for a
l o w t e m p e r a t u r e t r a n s i t i o n t o a collective
insulator at zero m a g n e t i c field in high
mobility
Si-MOSFETs.
This
collective
insulating
phase
has
the
transport
characteristics of a W i g n e r solid.
The t e m p e r a t u r e dependence of the zero
field resistance as a f u n c t i o n of carrier
density is also host t o s o m e more
f u n d a m e n t a l p h y s i c s : t h a t of scaling and
universality. For more t h a n t w o decades,
it has been generally a c c e p t e d t h a t , at
zero
magnetic
field,
all states
are
localized in a t w o - d i m e n s i o n a l s y s t e m for
an infinite sample as T—>0 | 3 5 | . In
c o n t r a s t , a three-dimensional s y s t e m can
sustain
a
metal-insulator
transition
because the electrons are localized only
w h e n the Fermi energy lies below a
mobility
edge
E c . The
conventional
w i s d o m in 2D s y s t e m s has recently been
questioned as a result of a number of
experimental results in s u p e r c o n d u c t i n g
thin f i l m s ,
and in h i g h - m o b i l i t y
SiMOSFETs
136-371.
In
addition,
a
theoretical s t u d y of n o n i n t e r a c t i n g 2D
electrons in a model disorder potential
w i t h a random set of special scatterers
s h o w e d t h a t , at zero magnetic field, the
s y s t e m is localized only w h e n Er < Ec
| 3 8 | . In material s y s t e m s w h e r e the range
of the s c a t t e r i n g centers is short (as in
MOSFETs), similar t o A z b e l ' s
model
potential, a " t r u e " zero m a g n e t i c field
metal-insulator t r a n s i t i o n m a y be a l l o w e d
in the limit of zero t e m p e r a t u r e . The
r e s i s t i v i t y as a f u n c t i o n of t e m p e r a t u r e
over a w i d e range of densities ( 7 . 1 2 - >
1 3 . 7 x 1 0 ' ° c m 2 ) in a h i g h - m o b i l i t y SiMOSFET
sample
(Si-12b;
fj m a x
=
3 . 0 x 10 4 c m 2 / V s ) can be made t o overlap
by scaling along the t e m p e r a t u r e axis.
The r e s i s t i v i t y can be represented in
t e r m s of a ratio T/T 0 w h e r e T 0 depends
only on the d e n s i t y . The data collapses
on t w o separate curves one for the
insulating side of the t r a n s i t i o n and the
other for the metallic side as s h o w n in
Fig. 9. One of the signatures of a phase
t r a n s i t i o n is the scaling of an appropriate
physical parameter. It w o u l d seem t h e n
that the results are in agreement w i t h
A z b e l ' s model but in c o n t r a d i c t i o n w i t h
that of A b r a h a m s and c o - w o r k e r s ; this
suggests that there is a " t r u e " metal
insulator t r a n s i t i o n in the t w o - d i m e n s i o n a l
e l e c t r o n s y s t e m in Si at zero magnetic
field.
Si-SiGe Si Q U A N T U M WELL
STRUCTURES
The e x p e r i m e n t a l results on high m o b i l i t y
Si-MOSFETS have been reproduced in at
least four d i f f e r e n t laboratories around
the w o r l d . H o w e v e r , there is only one
b a t c h of such samples and it is v e r y
d i f f i c u l t , w i t h o u t a large i n v e s t m e n t in
t i m e and m a n p o w e r , t o fabricate more of
these.
We
have
thus
turned
to
pseudomorphic
Si-SiGe-Si
heteros t r u c t u r e s w h i c h are g r o w n , either by
molecular beam e p i t a x y or ultra-high
vacuum
chemical
vapor
deposition
techniques,
in
a
large
number
of
laboratories and may be better suited for
s t u d y i n g W i g n e r crystallization.
The
important features of the p - t y p e Si-SiGeSi q u a n t u m w e l l s are that the 2D holes
have a large e f f e c t i v e hole mass, 0 . 4 2 m e
w h i c h is t w i c e that of electrons in the SiMOSFETs. This has been checked in our
samples by analysis of the l o w - f i e l d
Shubnikov-de Haas oscillations and by
c y c l o t r o n resonance 139-411. A l t h o u g h
the dielectric c o n s t a n t e ~ 12.6 is similar
to that of G a A s - A I G a A s h e t e r o s t r u c t u r e s ,
the s y m m e t r i c c o n f i n e m e n t of holes in
the SiGe w e l l can lead t o coupled 2D
hole gases. A s pointed out in Table 1, at
a carrier d e n s i t y of 2 x 1 0 " c m 2 in SiSiGe h e t e r o s t r u c t u r e s , the Wigner-Seitz
radius is identical t o that in Si-Si0 2 and
the q u a n t u m cold melting critical d e n s i t y
is t w i c e as large because of the larger
e f f e c t i v e mass!
observed in larger w e l l s but rather the
population of the heavy hole and the
light
hole ground
subbands.
This
interpretation is borne out by k * p
Luttinger
Hamiltonian
calculations
1411.
Table 3
The M B E - g r o w n S i - S i 0 8 / G e 0
Heterostructures
13 -Si
Surface
8
doped Si - 1 x 1 0 " cm
j
900 A
i - Si spacer
300 A
s
10 r - ,
Sio.B7GOo.13
(a)
10*
%
«,-6.46x10'° cm'1
«.
12.4xI0"cm!
Sample #
d
SiGe 1456
115 A
SiGe 1457
90 A
SiGe 1458
65 A
SiGe 1459
45 A
i - Si spacer
»
\
300 A
\
10'
B doped Si • 1 x 1 0 " c m J
500 A
X
-c
i - Si buffer
"-V4.
500 A
Q.
Si (100)
10°
n
•
10 1
to"
Fig. 9
10
.,
10
II
10
TIT,
,
10
10
,
Resistivity versus T/T 0 where T 0 is the
scaling parameter. The open symbols
correspond to the insulating side of
the transition while the closed ones
correspond to the metallic phase.
The
Si-Si087Ge0,3-Si
heterostructures
w e r e g r o w n on an n Si (100) substrate
by
molecular
beam
epitaxy.
The
symmetrically-doped o samples
were
g r o w n on a 5 0 0 ^ A i-Si buffer and
c o n s i s t e d of a 5 0 0 A Si layer modulationdoped w i t h boron acceptors at 10' 8 c m 3
and a 3 0 0 A i-Si setback on each side of
a Si 0 8 7 G e 0 , 3 q u a n t u m w e l l of thickness
d . A set of samples w a s g r o w n w i t h d
= 4 5 , 6 5 , 9 0 and o 11 5 Â. The cap layer
consisted of 4 0 0 A of B-doped Si. This
is s h o w n in Table 3.
There
is a
large peak
in the
longitudinal resistance at filling factor
3 / 2 f o l l o w e d by a deep m i n i m u m at
filling f a c t o r v = 1 . The Hall resistance
is not anomalous at the half-filled
Landau level and displays a w e l l
developed
plateau h/e 2 w h e n
the
longitudinal
resistance
is
at
its
minimum.
• For the narrower 9 0 and 65 Â w e l l s ,
there are large longitudinal resistance
peaks at both v = 3 / 2 and 5 / 2 , reentrant w i t h deep m i n i m a at v = 1
and 2.
• The t e m p e r a t u r e dependence of the
c u r r e n t - v o l t a g e characteristics taken at
v = 3 / 2 for the 65 Â w e l l reveal that
the onset of the large resistance
m a x i m a ( > > h/e 2 ) o c c u r s around 5 0 0
mK (see Fig. 11 ).
The samples w e r e patterned as Hall bar
s t r u c t u r e s 1 0 m m long and 2 m m w i d e .
O h m i c c o n t a c t s w e r e made using AI
e v a p o r a t i o n and annealing below the
eutectic point.
A number of u n e x p e c t e d results w e r e
obtained in these samples:
• The SdH oscillations in the 1 15 A w e l l
are t y p i c a l of t w o subband population
as s h o w n in Fig. 10. These are not
oscillations f r o m t w o independent hole
gases at each interface as
was
0
2
4
6
8
10
12
14
Magnetic Field (Tesla)
Fig. 10
Longitudinal resistance as a function
of magnetic field for different SiGe
quantum well widths at T - 25 mK.
67
. . . . . . . . .
200
150
•
;
!
;
:
50
•
;"""
S
•
520 mK
i
:
460mK
^ ^
:
240 mK
-150 -180 mK ^
130 mK
^
110 mK
I
-100
\
88. 70, 48 mK
^
-50
;
0
50
100
The curves also appear t o c o n v e r g e near
a critical resistivity of h/2e 2 . These
features are similar t o those observed in
s u p e r c o n d u c t i n g t h i n f i l m s of Bi as a
f u n c t i o n of thickness, and Si MOSFETs
and GaAs-AIGaAs heterostructures as a
f u n c t i o n of carrier d e n s i t y . Further s t u d y
of scaling parameters w i l l require the
variation of the d e n s i t y in the Si-SiGe-Si
heterostructures. From other w o r k [421,
w e k n o w t h a t the critical d e n s i t y in these
s y s t e m s is slightly above our f i x e d
d e n s i t y . W e m u s t also investigate the
role of disorder in the onset of these
transitions by s t u d y i n g higher m o b i l i t y
and hence higher Ge c o n t e n t samples.
150
Current (nA)
Fig. 11
•
, , ,,
Similar results are s h o w n in Fig. 12 for
t h e 9 0 Â w e l l w i t h the sub-threshold
resistance at v = 3 / 2 increasing by
t w o orders of m a g n i t u d e below 5 0 0
m K . the inset s h o w s the t h e r m a l
a c t i v a t i o n of t h e d i f f e r e n t i a l resistance
where dV/dl « e ^ 1 w i t h A = 0.47 K
in t h e t e m p e r a t u r e range above 1 0 0
mK.
A l t h o u g h these results have been t a k e n
at a f i x e d d e n s i t y ~ 2 x 1 0 " c m 2 , the
basic
features
of
large
longitudinal
resistances at half-filled Landau levels,
non-linear l - V characteristics w i t h l o w
threshold fields, and t h e r m a l a c t i v a t i o n of
the resistance are v e r y similar in nature
t o those in t h e Si-MOSFETS. In the light
of the scaling behavior of the zero
m a g n e t i c field resistance in Si-MOSFETs,
w e have also looked at the t e m p e r a t u r e
dependence of the longitudinal resistance
at zero field for d i f f e r e n t w e l l w i d t h s .
. . . .
30
• • - •
' ' • ' J
»
100
•
i
•
: :
•
'..... - * ... I
-
i
•
0
J"" '
1 /. Temperature 1 / K )
•
1
00
01
0.2
0.3
0.4
0.5
06
Temperature (K)
Fig. 12
Temperature dependence of the
differential resistance for the 90 A
well at v = 3/2 and B = 7.95 T. The
inset shows activated behavior in the
higher temperature scale.
A s s h o w n in Fig. 13, there is a t r a n s i t i o n
f r o m an insulating phase w h e r e p
decreases w i t h t e m p e r a t u r e for the 65 A
w e l l t o a metallic phase w h e r e
p„
decreases. w i t h t e m p e r a t u r e for the 9 0 A
and 1 1 5 A w e l l s . This is consistent w i t h
the f a c t t h a t the carrier d e n s i t y is
decreasing w i t h decreasing w e l l w i d t h .
68
«-A
Current voltage (l-V) characteristics
as a function of temperature fçr v =
3/2 at B = 7.75 T for the 65 A well.
Physics in Canada
M arch/Aprill 9 9 6
.
-I
90*
-
- — '
______
f
115 A
. . . .
ACKNOWLEDGMENTS
I
wish
to
acknowledge
fruitful
collaboration
with
a
number
of
colleagues: f r o m NRC- Don B r o w n , J o h n
Campbell,
Simon
Deblois,
Pawel
H a w r y l a k , Jennifer Lam, J.-P. Noël, and
Duncan S t e w a r t , f r o m the U n i v e r s i t y of
Oklahoma- J o h n Furneaux and Sergey
Kravchenko, f r o m SUNY in Buffalo- Bruce
M c C o m b e and his g r o u p and, finally,
f r o m the Institute f o r High T e m p e r a t u r e
Physics in M o s c o w - V l a d i m i r Pudalov
w h o provided the Si-MOSFETs and w a s
the driving f o r c e behind that w o r k .
REFERENCES
f
i . . . . .
1.0
W e have only begun t o explore the phase
diagram for the f o r m a t i o n of a W i g n e r
solid in t w o - d i m e n s i o n a l e l e c t r o n and
hole s y s t e m s . The mapping of t h e phase
boundaries as a f u n c t i o n of t e m p e r a t u r e ,
d e n s i t y , magnetic field and disorder is a
challenging t a s k . A s better
samples
become available, a fuller s t o r y on the
richness of the dilute d e n s i t y regime c a n
be w r i t t e n .
i . . . .
I . . .
1.
E. Wigner,
(1934).
Rev.
46,
1002
2.
R.S. Crandall and R.W. Williams,
Phys. Lett. A 34, 4 0 4 (1971).
3.
A.V. Chaplik,
395 (1972).
4.
A.S. Rybalko, B.N. Esselson, and Y.Z.
Kovdrya, Sov. J. Low Temp. Phys. 5,
4 5 0 (1979).
5.
C.C. Grimes and G. Adams,
Rev. Lett. 42, 795 (1979).
6.
R. Mehrottra, B.M. Guenin, and A.J.
Dahm, Phys. Rev. Lett. 48, 641
(1982).
7.
F. Gallet, G. Deville, A. Valdes, and
F.I.B. Williams, Phys. Rev. Lett. 53,
588 (1984).
8.
G. Deville, J. Low Temp. Phys. 72,
135 (1988).
9.
D. Ceperley, Phys. Rev. B 18, 3 1 2 6
(1978); B. Tanatar and D. Ceperley,
Phys. Rev. B 39, 5 0 0 5 (1989).
10.
For a review see Physics of the
Electron Solid, edited by S.T. Chui,
International
Press
Inc.
Boston
(1994).
11.
K. Kajita, Jpn. J. Appl. Phys. 25,
1943 (1987); Surf Sci. 196, 29
(1988).
12.
H.-W. Jiang and A.J. Dahm, Phys.
Rev. Lett. 62, 1396 (1989); Surf.
Sci. 229, 3 5 2 (19901.
13.
E.Y. Andrei, G. Deville, D.C. Glattli,
F.I.B.
Williams,
E.
Paris,
and
B. Etienne, Phys. Rev. Lett. 60, 2 7 6 5
(1988).
.
1.5
Temperature (K)
Fig. 13
Phys.
Temperature dependence of the
longitudinal resistivity in a vanishing
magnetic field for different SiGe
quantum well widths.
Sov.Phys.
JETP
35,
CONCLUSION
The w o r k on Si-MOSFETs has provided a
phase diagram for the f o r m a t i o n of a
q u a n t u m W i g n e r c r y s t a l at zero magnetic
field as a f u n c t i o n of disorder. It w a s also
established that a fully spin-polarized
W i g n e r c r y s t a l could exist re-entrantly
w i t h a partially polarized q u a n t u m liquid
or gas in the q u a n t u m Hall e f f e c t regime
in very high m o b i l i t y samples o n l y . The
s t u d y of the re-entrant insulating phase in
s e m i c o n d u c t o r heterostructures has also
led t o the d e f i n i t i o n of a n e w t y p e of
insulator, " t h e Hall i n s u l a t o r " | 4 3 | , for
w h i c h the Hall resistivity remains metallic
w h i l e the longitudinal resistivity becomes
infinite. The s y s t e m par excellence t o
s t u d y t h e W i g n e r c r y s t a l state is one
w h e r e the e f f e c t i v e mass is large, the
dielectric c o n s t a n t and the a m o u n t of
disorder are small, the carrier d e n s i t y is
tunable and the material s y s t e m imposes
some sort of inherent coupling either
w i t h non-degenerate valleys as in SiMOSFETs, or by lifting the degeneracy
between
the
symmetric
and
antis y m m e t r i c states t h r o u g h t h e valence
band anisotropy as in the Si-SiGe s y s t e m .
Finally,
there
is
now
mounting
experimental
evidence
that
the
Abrahams-Anderson-LicciardelloRamakrishnan theory for w h i c h a metalinsulator t r a n s i t i o n in an infinite 2D
s y s t e m , at zero magnetic field as T - » 0 is
forbidden, is inappropriate in 2 D s y s t e m s
w i t h short range scatterers.
(continued o n page 7 1 )
Phys.
NOUVELLE SOURCE DE PLASMA POUR LE TRAITEMENT DES MATÉRIAUX: MAGNÉTOPLASMA À ONDE
DE SURFACE
par
Joëlle M a r g o t , Groupe de Physique des Plasmas, Département de Physique, Université de M o n t r é a l , C.P. 6 1 2 8 , Succ. Centre-ville,
M o n t r é a l , Québec H3C 3 J 7 , adresse électronique: m a r g o t j @ e r e . u m o n t r e a l . c a
INTRODUCTION
A u cours des vingt dernières années, on a
v u croître de f a ç o n considérable l ' e m p l o i
des plasmas pour le t r a i t e m e n t
des
matériaux aussi bien dans les secteurs de
haute technologie, c o m m e par exemple en
microélectronique et en photonique, que
dans les industries plus traditionnelles
(e.g., métallurgie et textile).
Il f a u t se
rappeler que dans le passé, les applications
des plasmas au t r a i t e m e n t des matériaux
se sont développées sous l'égide de la
c o m m u n a u t é des utilisateurs, ceux-ci ayant
fait appel aux plasmas pour pallier les
limitations des m é t h o d e s c o n v e n t i o n n e l l e s .
Les percées dans le d o m a i n e se sont d o n c
appuyées sur des m o y e n s plus ou moins
empiriques de sorte que le f o n d e m e n t
scientifique de ces applications d e m e u r e
encore peu substantiel.
Le progrès que
l ' o n peut attendre d ' u n e telle d é m a r c h e est
par conséquent limité et il est devenu
nécessaire de
mieux
comprendre
le
f o n c t i o n n e m e n t des sources de plasma
utilisées, d ' e n concevoir de nouvelles et de
modéliser de f a ç o n adéquate à la fois le
plasma et l ' i n t e r a c t i o n plasma-surface si
l ' o n veut relever les défis posés en
m i c r o é l e c t r o n i q u e et en photonique. Bien
sûr, c e t t e recherche est de nature t o u t à
fait f o n d a m e n t a l e et elle requiert une
expertise en physique des plasmas, aussi
bien en m o d é l i s a t i o n q u ' e n caractérisation,
et une i n t e r a c t i o n
étroite
avec
les
spécialistes
des procédés
et de
la
caractérisation des surfaces. T o u t ceci a
s t i m u l é au cours des dernières années des
a c t i v i t é s de recherche portant sur la
physique des plasmas dits froids et des
plasmas
réactifs dans de
nombreux
laboratoires à t r a v e r s le monde.
Pour notre part, dans le c o n t e x t e général
présenté ci-dessus, nous avons mis au
point une source de plasma originale,
basée sur la p r o p a g a t i o n des ondes de
surface et à laquelle on adjoint un
c o n f i n e m e n t m a g n é t i q u e . Les propriétés
de c e t t e source sont mises à profit pour
graver
des
couches
minces
à des
dimensions
sous-micrométriques.
La
conception
de
cette
source,
sa
caractérisation
et
sa
modélisation
constituent
un
volet
important
des
a c t i v i t é s du Groupe de Physique des
Plasmas de l ' U n i v e r s i t é de M o n t r é a l . Dans
cet article, nous d é c r i v o n s b r i è v e m e n t les
propriétés du plasma ainsi produit ainsi que
l ' i n f l u e n c e sur les paramètres du plasma de
la
présence
d'un
substrat.
Nous
e x a m i n o n s également les p e r f o r m a n c e s de
ce plasma pour la r e p r o d u c t i o n de m o t i f s
s o u s - m i c r o m é t r i q u e s ( 0 , 2 p m ) dans du
tungstène.
NOUVELLES SOURCES DE P L A S M A POUR
LA GRAVURE EN MICROÉLECTRONIQUE
La source de plasma
majoritairement
e m p l o y é e en g r a v u r e des m a t é r i a u x , pour
prendre cet e x e m p l e , est la décharge
capacitive. Bien que ce t y p e de plasma
soit e m p l o y é de f a ç o n routinière dans la
f a b r i c a t i o n des m i c r o c i r c u i t s , entre autres
parce q u ' i l permet le t r a i t e m e n t simultané
de plusieurs s u b s t r a t s , il s o u f f r e de sévères
limitations.
D ' u n e part, la densité de
particules chargées est faible ( t y p i q u e m e n t
9
1 0 - 1 0 ' ° ions par cm 3 ) et d ' a u t r e part, ce
t y p e de source ne permet pas un bon
contrôle du flux d ' i o n s vers la surface. Or,
il s ' a v è r e q u ' u n tel contrôle est devenu
nécessaire pour atteindre l'anisotropie de
g r a v u r e recherchée ainsi que l ' o p t i m i s a t i o n
des autres paramètres de gravure.
De
nouvelles sources de plasma ont vu le jour
pour mieux répondre aux o b j e c t i f s de plus
en plus exigeants dans ce domaine. En
bref, il s'agit de produire une source de
plasma
relativement
dense
tout
en
p e r m e t t a n t de contrôler adéquatement le
flux d ' i o n s frappant la surface, et ceci
indépendamment
du
mécanisme
de
création du plasma. Une source telle que
la f a m e u s e décharge dite de résonance
c y c l o t r o n i q u e électronique (RCE) en est un
exemple. Il s'agit d ' u n e source micro-onde
( 2 , 4 5 GHz) f o n c t i o n n a n t à très basse
pression ( 1 0 m t o r r et moins) et dont la
densité d ' i o n s peut atteindre selon les
conditions plusieurs 1 0 " c m 3 avec un
degré d ' i o n i s a t i o n souvent supérieur à 1 % .
Le f o n c t i o n n e m e n t à très basse pression
est rendu possible grâce à la présence d ' u n
c h a m p magnétique statique (environ 8 7 5
gauss) qui permet de confiner les particules
chargées
et
assure
également
le
m é c a n i s m e de transfert d'énergie ondeplasma.
Les avantages de ce t y p e de
plasma sont notoires.
A i n s i , la grande
densité de particules chargées permet
d'assurer un taux élevé de gravure assistée
par les ions.
A u c u n e électrode interne
n ' é t a n t présente dans la décharge, les
risques de c o n t a m i n a t i o n sont minimisés.
La d i f f é r e n c e de potentiel entre la surface
gravée et le plasma est en général
inférieure à 2 0 v o l t s , une valeur très endessous de celle rencontrée dans les
décharges capacitives. Enfin, la pression
très faible permet de limiter le n o m b r e de
collisions subies par les ions dans la gaine
de plasma. Ainsi, on préserve mieux la
directionnalité du m o u v e m e n t des ions
dans la gaine ce qui favorise l'anisotropie
de gravure.
D ' a u t r e s t y p e s de décharges similaires à la
source RCE ont également été proposées
c o m m e , par e x e m p l e , le plasma hélicon
dont
le
principe
de
fonctionnement
demeure t o u t à fait comparable. Ce plasma
est produit à des fréquences radio (e.g.,
1 3 , 5 6 MHz) et nécessite également un
champ magnétique;
on note cependant
que ce c h a m p peut être beaucoup plus
faible que celui e m p l o y é pour les décharges
RCE. Pour des conditions comparables de
pression, de d i a m è t r e de tube à décharge
et d ' i n t e n s i t é de c h a m p m a g n é t i q u e , la
densité
de
particules
chargées
est
c o m p a r a b l e dans les deux t y p e s de plasma.
Pour notre part, nous avons souhaité
capitaliser sur l'expérience que nous avons
des plasmas produits par des ondes de
surface, pour produire une nouvelle source
avec des caractéristiques comparables à
celles des plasmas p r é c é d e m m e n t décrits.
Dès 1 9 9 2 , nous avons mis sur pied un
p r o t o t y p e de réacteur destiné à la gravure
de matériaux (RCE4).
Son schéma est
présenté sur la figure 1.
Figure 1. S c h é m a
du r é a c t e u r
RCE4
(magnétoplasma à onde de surface)
Le réacteur est alimenté par un plasma à
onde de surface à 2 , 4 5 GHz produit dans
un tube de silice f o n d u e (quartz) de 15 c m
de diamètre. Ce tube pénètre dans une
enceinte métallique de 28 c m de d i a m è t r e
le long de laquelle sont disposées plusieurs
fenêtres destinées à visualiser le plasma et
à insérer des diagnostics. Un ensemble de
1 2 solénoïdes est disposé le long du tube
et du réacteur. L ' e s p a c e m e n t entre les
bobines a été choisi de sorte que le c h a m p
magnétique
demeure
homogène
sur
environ 7 0 c m , incluant la source.
Cet
aspect de la c o n c e p t i o n du dispositif
e x p é r i m e n t a l est basé sur le fait que les
études de d i s t r i b u t i o n en vitesse des ions
dans des réacteurs de t y p e RCE ou hélicon
m o n t r e n t que le m o u v e m e n t des ions est
très influencé par l ' o r i e n t a t i o n des lignes
de c h a m p magnétique: les ions ont
tendance à suivre ces lignes.
Or, pour
atteindre un bon c o n t r ô l e du m o u v e m e n t
des ions vers la surface à traiter, il est
n e t t e m e n t préférable que ceux-ci frappent
la surface à la normale.
L'utilisation
fréquente de lignes de c h a m p divergentes
dans les m a g n é t o p l a s m a s est un obstacle
à la recherche de l'anisotropie en gravure
de c o u c h e s m i n c e s .
Bien que les études que nous avons
menées
jusqu'à
présent
se
soient
essentiellement limitées à une fréquence
micro-onde ( 2 , 4 5 GHz), le plasma produit
par onde de surface présente l ' a v a n t a g e
notoire de pouvoir f o n c t i o n n e r à n ' i m p o r t e
quelle fréquence.
C ' e s t d'ailleurs c e t t e
extraordinaire flexibilité, bien adaptée à des
études paramétriques, qui a permis à ce
t y p e de plasma d ' a c q u é r i r ses lettres de
noblesse, particulièrement
en ce qui
concerne la m o d é l i s a t i o n des décharges de
haute fréquence (HF).
69
CARACTÉRISTIQUES DU MAGNÉTOPLASMA
À ONDE DE SURFACE
La figure 2 m o n t r e u n e x e m p l e de
d i s t r i b u t i o n en vitesse des ions métastables
d ' a r g o n dans la d i r e c t i o n parallèle à l ' a x e de
la colonne de plasma dans un dispositif
similaire à celui présenté ci-dessus (RCE5).
Ces mesures ont été réalisées au m o y e n
d ' u n e m é t h o d e de fluorescence induite par
laser.
Figure 2. Fonction de distribution en énergie
des
ions
métastables
d'argon
obtenues dans le réacteur FICE5 au
moyen
d'une
méthode
de
fluorescence induite par laser. Noter
que les profils ne sont
pas
déconvolués pour tenir compte de
l'effet Zeeman et de la largeur de la
raie du laser.
O n y remarque que les ions suivent une
d i s t r i b u t i o n gaussienne centrée autour de
zéro. A i n s i , pour un c h a m p magnétique
axialement u n i f o r m e , les ions ont une très
faible vitesse de dérive axiale. À t i t r e de
c o m p a r a i s o n , nous avons représenté sur la
m ê m e f i g u r e les d i s t r i b u t i o n s de vitesse
obtenues dans des régions de c h a m p
m a g n é t i q u e décroissant et croissant. Dans
le premier cas, les ions sont accélérés loin
de la source alors q u e dans le second, les
ions ont t e n d a n c e à revenir vers la source.
Ces résultats illustrent
bien le rôle
extrêmement
important
que joue
la
configuration
du
champ
magnétique
statique sur le m o u v e m e n t des ions. La
c o n c l u s i o n évidente de ces résultats est
que pour tirer t o u s les bénéfices de
l ' u t i l i s a t i o n d ' u n c h a m p magnétique de
c o n f i n e m e n t , il est préférable d ' a v o i r des
lignes
de
champ
magnétique
aussi
u n i f o r m e que possible. Ceci permet de
limiter la dérive axiale des ions au m i n i m u m
et donne à l ' u t i l i s a t e u r plus de latitude pour
contrôler i n d é p e n d a m m e n t du plasma le
m o u v e m e n t des ions vers la surface à
traiter, par exemple au m o y e n d ' u n e
polarisation auxiliaire (et maîtrisée) du
substrat.
Le m a g n é t o p l a s m a a été diagnostiqué au
m o y e n de plusieurs m é t h o d e s incluant des
sondes
électrostatiques,
des
ondes
acoustiques ioniques et diverses m é t h o d e s
spectroscopiques.
Nous avons ainsi pu
m o n t r e r que la densité des ions positifs
pouvait atteindre localement 1 0 , J c m 3
dans l ' a r g o n et la t e m p é r a t u r e
des
électrons quelques eV.
Dans un gaz
c o m m e le SF„ utilisé pour la g r a v u r e du
t u n g s t è n e , on a o b t e n u des valeurs
comparables
pour
la densité
et
la
température;
o n a également mis en
70
Physics in Canada
M arch/Aprill 9 9 6
évidence par photo-détachement induit par
laser une f o r t e c o n c e n t r a t i o n
d'ions
négatifs, leur densité étant supérieure à
celle des électrons à des pressions de
seulement quelques mtorr.
Nous avons utilisé une source similaire,
mais de plus petites d i m e n s i o n s pour
e f f e c t u e r une étude du bilan énergétique
de la décharge 11). Nous avons ainsi pu
m o n t r e r que le bilan énergétique s'améliore
l o r s q u ' u n c o n f i n e m e n t magnétique est
appliqué à la décharge, c o m m e on pouvait
s ' y attendre, la présence d ' u n c h a m p
magnétique
réduisant
les pertes
de
particules chargées.
Un modèle de
m a g n é t o p l a s m a r é c e m m e n t élaboré [2]
permet d'ailleurs de c o n f i r m e r un certain
n o m b r e de nos observations. Cependant,
c o n t r a i r e m e n t à ce qui est largement
a f f i r m é dans la littérature, le fait de
f o n c t i o n n e r à la résonance c y c l o t r o n i q u e
électronique ne constitue pas un avantage
en t e r m e s de bilan d'énergie. En f a i t , plus
le c h a m p magnétique est intense, meilleur
est le rendement énergétique. Les valeurs
mesurées de la puissance absorbée par
é l e c t r o n dans notre plasma ont été
utilisées pour d é m o n t r e r que l'ensemble
des m a g n é t o p l a s m a s HF obéissent aux
m ê m e s règles physiques; ainsi, pour des
conditions identiques de f o n c t i o n n e m e n t ,
le bilan énergétique demeure le m ê m e pour
n ' i m p o r t e quel magnétoplasma HF.
INTERACTION P L A S M A - S U R F A C E
Nous avons étudié l'influence de la
présence
d'un
substrat
sur
les
caractéristiques en v o l u m e du plasma [3].
— Sans substrat
• Acier
« Al
10
?J; .
•ï
Tin ^mm ... —
Position r a d i a i t ( a n )
l'aluminium et de
pression (7 mtorr).
l'acier
à
plus
haute
Outre son influence sur la concentration en
fluor
atomique dans la décharge, la
présence d'un substrat modifie de façon
importante celle du soufre moléculaire tel
qu'illustré sur la figure 3.
Sur
ce
graphique
est
reportée
la
c o n c e n t r a t i o n de S 2 en f o n c t i o n de la
position à partir du substrat pour d i f f é r e n t s
matériaux.
On
y
remarque
un
accroissement de la c o n c e n t r a t i o n de S 2
non seulement au voisinage i m m é d i a t du
s u b s t r a t , mais également à grande d i s t a n c e
de celui-ci. À partir de ces résultats ainsi
que
de
mesures
complémentaires
e f f e c t u é e s en post-décharge temporelle, on
a pu montrer que la présence d ' u n
substrat, et particulièrement d ' u n substrat
de t u n g s t è n e , influence l'ensemble de la
chimie du réacteur, incluant le c o e f f i c i e n t
de collage de ses parois d ' a c i e r . En o u t r e ,
nous avons pu m e t t r e en évidence que le
soufre moléculaire est
principalement
détruit
par
impact
électronique
contrairement à ce qui a été observé dans
une décharge capacitive de t y p e RIE
(Reactive Ion Etching) [ 4 | , ceci résultant
bien sûr du fait que le m a g n é t o p l a s m a est
considérablement
plus dense que la
décharge de t y p e capacitif.
GRAVURE SOUS-MICROMÉTRIQUE
TUNGSTÈNE
DU
La source que nous avons conçue nous a
permis d ' e f f e c t u e r , en utilisant un plasma
de SF 6 , la g r a v u r e de m o t i f s sousmicrométriques
de t u n g s t è n e
à des
t e m p é r a t u r e s de substrat variant de - 4 5 ° à
+ 1 5° I 5 | . A i n s i , nous avons pu reproduire
des m o t i f s de très petites d i m e n s i o n s ( 0 , 2
//m) sans faire appel à une polarisation
externe du s u b s t r a t .
Dans une telle
situation, les ions interagissant avec la
surface ont une énergie relativement faible,
ce qui réduit les d o m m a g e s causés à la
surface. Une photographie de m o t i f s de
0 , 2 / / m est présentée sur la figure 4. La
gravure demeure anisotrope tant que la
pression est inférieure à une valeur seuil,
f o n c t i o n de la t e m p é r a t u r e de la surface.
Ainsi, pour une t e m p é r a t u r e de -20°, le
seuil se situe autour de 0 , 7 5 m t o r r alors
q u ' i l est plutôt de 1,5 m t o r r lorsque la
t e m p é r a t u r e est abaissée à -45°.
Figure 3. Densité de soufre moléculaire S, dans
le plasma en présence de différents
substrats. Le substrat est situé à -1
cm sur l'abscisse de ce graphique.
Cette étude a été menée sur un plasma de
SF 6
au
moyen
d'une
méthode
de
fluorescence induite par laser et d'une
méthoded'actinométrierésoluespatialement
avec double procédure de normalisation; les
e s p è c e s e x a m i n é e s sont, d'une part, le fluor
atomique et, d'autre part, le
soufre
moléculaire
S2,
formé
en
grande
concentration dans ce type de plasma. Les
résultats de cette étude ont montré que le
fluor atomique est fortement c o n s o m m é par
le silicium, c o m m e on s'y
attendait,
contrairementaux matériaux plus inertes visà-vis d e s gaz fluorés, c o m m e l'aluminium ou
l'acier inoxydable. Le tungstène, q u a n t a lui,
n'a pas une influence systématique sur cette
consommation
qui
peut
être
aussi
importante que celle du silicium à basse
pression (1 mtorr) ou comparable à celle de
Figure 4. Photographie de motifs de tungstène
ayant 0,2 /vm de largeur, obtenus à
partir d'une image par microscope
électronique.
Les résultats o b t e n u s m o n t r e n t que notre
réacteur
possède
d'excellentes
caractéristiques. En particulier, le fait de
ne pas devoir recourir à une polarisation
auxiliaire du substrat pour atteindre une
anisotropie parfaite c o n s t i t u e un atout
majeur par rapport à d ' a u t r e s t y p e s de
sources. Nous pensons que le fait que le
c h a m p m a g n é t i q u e soit u n i f o r m e dans la
région où se situe le s u b s t r a t , est à
l'origine des excellentes p e r f o r m a n c e s de
notre réacteur en t e r m e s de gravure.
14)
I5|
CONCLUSION
Nous avons mis au point une nouvelle
source de plasma dont les caractéristiques
sont bien adaptées à la r e p r o d u c t i o n de
m o t i f s s o u s - m i c r o m é t r i q u e s . Le travail que
nous avons e f f e c t u é s ' e s t situé non
seulement
du
point
de
vue
des
applications, mais également sur le plan de
la physique plus f o n d a m e n t a l e , grâce à des
études approfondies des propriétés de la
décharge. Clairement, beaucoup reste à
faire, particulièrement
en t e r m e s
de
modélisation du plasma et de l ' i n t e r a c t i o n
plasma-surface que nous n ' a v o n s pour
l'instant q u ' é b a u c h é e s . A u cours des
prochaines années, il nous restera à mieux
maîtriser ces deux aspects en m e n a n t des
études e x p é r i m e n t a l e s et théoriques de
f r o n t . Bien sûr, ce défi est de taille, mais
nous s o m m e s c o n v a i n c u s que
cette
approche est la seule qui soit valable pour
améliorer
notablement
les
procédés
assistés par plasma.
REMERCIEMENTS
L'auteur
tient
à
exprimer
sa
reconnaissance à t o u t e s les personnes,
collaborateurs, stagiaires, étudiants et
techniciens, ayant été impliquées à divers
t i t r e s dans les t r a v a u x résumés ci-dessus.
En particulier, les c o n t r i b u t i o n s de M M . M.
Chaker (INRS-Énergie et Matériaux) et M .
M o i s a n (Université de Montréal) sont
v i v e m e n t remerciées ainsi que celles de
M m e s C. Barbeau et I. Pérès et de M . E.
Gat (stagiaires p o s t d o c t o r a u x ) .
L'auteur
tient également à exprimer sa g r a t i t u d e à
M m e A . Dallaire et M . M . Fortin (étudiants
de 2° cycle) et M M . F. Bounasri et L. StOnge (étudiants de 3° cycle). Enfin, une
reconnaissance particulière est accordée à
R. Grenier, R. L e m a y , R. M a r t e l et F. Roy
pour leur e x c e p t i o n n e l soutien technique.
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Phys.
71
EVALUATION OF THE ACID DEPOSITION AND OXIDANT MODEL W I T H OZONE AND SULPHUR DIOXIDE
DATA FROM HIGH ELEVATION SITES
by
C . M . Bariic, R.S. Schemenauer, K. G. Anlauf and K.I.A. M a c Q u a r r i e
A t m o s p h e r i c Environment Service, 4 9 0 5 D u f f e r i n Street, D o w n s v i e w , Ontario, C anada, M 3 H 5 T 4
ABSTRACT
M i x i n g ratios of 0 3 , measured c o n t i n u o u s l y
at t w o high elevation ( 8 5 0 m - m s l ) sites
and one valley ( 2 5 0 m-msl) site in s o u t h e r n
Quebec, Canada, during the s u m m e r of
1 9 8 8 and spring of 1 9 9 0 , and m i x i n g
ratios of S 0 2 measured during the spring of
1 9 9 0 at one high elevation site are
c o m p a r e d w i t h the predictions of the A c i d
D e p o s i t i o n and Oxidant M o d e l ( A D O M ) .
These sites are representative of rural
areas d o w n w i n d of major anthropogenic
source regions. This is the first evaluation
of a regional-scale Eulerian transport and
c h e m i s t r y model using data f r o m Canadian
high elevation sites.
The observations s h o w higher average 0 3
m i x i n g ratios in the spring t h a n the
s u m m e r at b o t h the more northerly high
elevation site and at the valley site. The
model results for c o m p a r a b l e elevations
s h o w a d i f f e r e n t seasonal t e n d e n c y , w i t h
higher average 0 3 s e e n in the s u m m e r . In
the s u m m e r the average modelled ozone
m i x i n g ratio is about 14 ppbv higher t h a n
the average measured ozone m i x i n g ratio
for the m o r e northerly high elevation site,
and 8 ppbv higher for the more s o u t h e r l y .
In c o n t r a s t , the average modelled ozone
m i x i n g ratio for t h e spring is 4 t o 6 ppbv
l o w e r t h a n the average measured ozone
m i x i n g ratio for all three sites. In b o t h
seasons the range of the hourly ozone
m i x i n g ratios observed at the
high
elevation sites is greater t h a n
that
predicted by the model. The measured and
modelled sulphur dioxide hourly m i x i n g
ratios, averaged over a f i v e w e e k period,
are b o t h near 1 . 2 9 ppbv. In the spring,
the diurnal variations in 0 3 and S 0 2 are
w e l l represented by the model.
The ability of the model t o predict days
w i t h t h e upper or l o w e r quartile of 0 3
m i x i n g ratios is assessed using the True
Skill Statistic (TSS), w i t h the highest skill
(TSS = .77) s h o w n for l o w 0 3 events in the
s u m m e r at the high elevation sites and the
l o w e s t skill (TSS = .27) s h o w n for the
valley site for b o t h high and l o w 0 3
episodes in the spring. The upper quartile
0 3 events at b o t h high elevation sites are
predicted w i t h a TSS of 0 . 5 6 or greater for
b o t h seasons. The model s h o w s poor skill
at predicting the daily trends in S 0 2 .
It is r e c o m m e n d e d that the s e n s i t i v i t y of
the model o u t p u t t o the choice of
boundary conditions for 0 3 , the m i x i n g
processes in t h e l o w e r 1 k m of the
atmosphere during the s u m m e r season,
and t h e loss of 0 3 in the nocturnal
inversion in s u m m e r be further investigated
since
these
processes
appear
to
significantly
influence
the
ADOM
predictions of ozone m i x i n g ratio.
INTRODUCTION
One current problem in a t m o s p h e r i c
science is understanding the c o m p l e x
72
Physics in Canada
M arch/Aprill 9 9 6
linkage b e t w e e n emissions of specific
pollutant species and the resultant impact
of the reaction products of these species
on v e g e t a t i o n , animals, humans and
c l i m a t e . To a large extent m a n ' s influence
on the e n v i r o n m e n t is under the control of
policy makers, and changes are possible
w i t h the appropriate trade-off in e c o n o m i c s
and lifestyle. T w o gas-phase species of
current c o n c e r n in the l o w e r troposhere are
ozone ( 0 3 - an oxidant and greenhouse
gas) and sulphur dioxide ( S 0 2 - the
precursor t o sulphate w h i c h is one of the
primary
causes
of
the
acidity
in
precipitation and fog).
M a t h e m a t i c a l air-quality models w h i c h
incorporate
complex
chemistry
and
m e t e o r o l o g y have been developed t o
provide guidance in f o r m u l a t i n g the m o s t
appropriate control strategies for air
pollutants w i t h regional i m p a c t s . The A c i d
Deposition and Oxidant Model ( A D O M ) , a
regional-scale
Eulerian
atmospheric
transport and c h e m i s t r y model,
was
developed in a cooperative e f f o r t f u n d e d
by the Canadian federal g o v e r n m e n t , the
Province of Ontario, the Electric Power
Research
Institute,
and the
Federal
Republic of Germany t o aid in the
understanding of the impact of emission
controls
on
acid
deposition
and
ground-level
oxidant
concentrations
( V e n k a t r a m et al., 1 9 8 8 ; Karamchandani
and V e n k a t r a m , 1 9 9 2 ) .
Models such as
A D O M m u s t be carefully evaluated w i t h
field data so that their performance can be
assessed before the predictions can be
used w i t h confidence. The Eulerian Model
Evalation Field Study (EMEFS) w a s carried
out f r o m June 1 9 8 8 t o M a y 1 9 9 0 at
surface sites in eastern N o r t h A m e r i c a to
gather data for the evaluation of A D O M
and the Regional A c i d Deposition Model,
w h i c h w a s developed for use in the U . S . A .
(e.g., Byun and Dennis, 1 9 9 5 ) . From July
15 t h r o u g h A u g u s t 3 1 , 1 9 8 8 and M a r c h
15 t h r o u g h April 3 0 , 1 9 9 0 , enhanced
observations,
including
aircraft
m e a s u r e m e n t s of 0 3 and S 0 2 m i x i n g ratios
at altitudes f r o m 0 . 5 t o 5 k m , w e r e made
in central Ontario t o support the model
evaluation. Evaluations of the performance
of A D O M during the s u m m e r period have
been made w i t h aircraft data (Macdonald
et al., 1993) and w i t h 0 3 profiles to 1 5 km
obtained w i t h ozonesondes and differential
absorption lidar (Hoff et al., 1 9 9 5 ) .
Observations of meteorological parameters
and ozone mixing ratios have been made at
high elevation rural sites in forested areas
of Quebec since 1 9 8 6 as part of the
C h e m i s t r y of High Elevation Fog (CHEF)
program
(Schemenauer,
1986),
with
sulphur dioxide monitored at one site f r o m
Sept. 1 9 8 9 t h r o u g h J u l y 1 9 9 0 .
In this
paper, data f r o m these sites, located 3 0 0
to 5 0 0 k m east of the aircraft s t u d y , are
c o m p a r e d w i t h the results of A D O M for
the t w o EMEFS enhanced o b s e r v a t i o n
periods. W h e r e a s the aircraft observations
consist of a c o m b i n a t i o n of horizontal
transects up t o 2 5 0 k m for t i m e s of about
1 hour and vertical profiles over specific
surface sites taken once or t w i c e per d a y ,
the CHEF data provide continuous hourly
m e a s u r e m e n t s w h i c h permit
sensitive
t e s t i n g of the model at an altitude
equivalent t o an elevated layer of t h e
model throughout the long t i m e periods for
w h i c h the model is e x p e c t e d t o have g o o d
predictive skill (e.g. seasonal means, etc.).
The CHEF high elevation surface sites are
exposed t o higher w i n d speeds (Bridgman
et al., 1994) and have generally higher
m i x i n g ratios and smaller diurnal variations
in 0 3 t h a n l o w elevation surface sites. The
CHEF m o u n t a i n sites have long records of
ozone and meteorological parameters, as
w e l l as f o g
and
precipitation
data
(Schemenauer et al., 1 9 9 5 ) , w h i c h can be
v e r y c o m p l e m e n t a r y t o data f r o m standard
surface n e t w o r k s , aircraft and remote
sensing in further model evaluation.
METHOD
The M e a s u r e m e n t s
The 0 3 m i x i n g ratios w e r e measured at
Roundtop M o u n t a i n (RTR, 4 5 ° 0 5 ' 1 7 " N ,
7 2 ° 3 3 ' 0 9 " W , 8 4 5 m - m s l ) , a nearby valley
site (RTV, 4 5 ° 0 4 ' 3 2 " N , 7 2 ° 4 0 ' 3 3 " W , 2 5 0
m-msl)
and
Mont
Tremblant
(MT,
4 6 ° 1 2 ' 5 0 " N, 7 4 ° 3 3 ' 2 0 " W , 8 6 0 m - M S L ) .
The S 0 2 m e a s u r e m e n t s w e r e made at
RTR.
These sites are northeast of
w i d e s p r e a d sources of
anthropogenic
pollution in N o r t h A m e r i c a (Benkovitz et
al., 1 9 9 4 ) . M i n i m a l anthropogenic a c t i v i t y
is seen t o the north of M T , and this site is
considered
to
be
representative
of
background conditions w h e n under the
influence of northerly air.
Ozone w a s d e t e c t e d w i t h TECO 4 9 u . v .
photometric
analyzers equipped
with
automatic
pressure
and
temperature
c o m p e n s a t i o n , and calibrated w i t h sources
traceable t o NIST transfer standards.
Sulphur dioxide w a s m o n i t o r e d w i t h a
TECO 4 3 A pulsed fluorescence analyzer
w h i c h w a s calibrated w i t h a p e r m e a t i o n
tube dilution s y s t e m .
The sample inlets
w e r e located 3 m above g r o u n d level. The
signals f r o m the 0 3 and S 0 2 analyzers
w e r e sampled every 5 seconds and
recorded on a data logger as 15-minute
averages.
For
this
analysis,
hourly
averages w e r e derived for b o t h species.
Due t o routine zeroing of the S 0 2 analyzer
for 3 0 minutes w i t h i n each even hour
(UTC) hourly averages are available for odd
hours only. The d e t e c t i o n limit for S 0 2 is
estimated at 0 . 1 parts per billion by
v o l u m e (ppbv) and the hourly 0 3 m i x i n g
ratio is k n o w n t o 1 ppbv. For the t i m e
periods
considered,
the
CHEF
data
recovery is 1 0 0 % for 0 3 and S 0 2 , except
for the s u m m e r of
1988 when
03
m e a s u r e m e n t s are available only 9 0 % of
the t i m e at RTR and 9 8 % of the t i m e at
RTV. In this evaluation, model results are
not included for periods of
missing
observations. The e f f e c t of the e x c l u s i o n
of one-half the modelled results for S 0 2
w a s investigated. The daily averages of
S 0 2 mixing ratio w e r e calculated w i t h
results for all hours and t h e n again w i t h
the odd hours o n l y .
The t w o sets of
values
were
correlated
with
an
r2
exceeding 0 . 9 9 9 and w i t h mean, median
and m a x i m u m d i f f e r e n c e s of 0 . 0 2 , 0 . 0 1
and 0 . 1 p p b v , r e s p e c t i v e l y .
The locations of the high elevation sites
w e r e c h o s e n t o provide exposure t o the
prevailing w i n d d i r e c t i o n s , and t o be
relatively elevated and isolated c o m p a r e d
w i t h the surrounding terrain. These sites
are regularly i m p a c t e d by l o w level s t r a t u s
and c u m u l u s , and it is clear f r o m the
m o t i o n of these cloud fields t h a t the sites
are under the influence of air d r i v e n by
s y n o p t i c w i n d s c h a r a c t e r i s t i c of elevated
altitudes. Upslope and d o w n s l o p e w i n d s
are i m p o r t a n t only under the c o n d i t i o n of
v e r y l o w s y n o p t i c w i n d s . The a m o u n t of
orographic lift is small c o m p a r e d w i t h the
m i x i n g in the boundary layer, and the high
elevation sites w i l l be located w i t h i n the
mixed
boundary
layer
during
most
a f t e r n o o n periods.
The M o d e l and Data A n a l y s i s
The model d o m a i n c o n s i s t s of 3 3 x 3 3 grid
squares, each a p p r o x i m a t e l y
127x127
k m 2 , c o v e r i n g eastern Canada and the
United States, w i t h 12 layers in the
vertical spanning 1 t o 1 0 , 0 0 0 m-agl. A
grid cell refers t o the v o l u m e occupied by
one layer in one grid square. The o u t p u t
consists of hourly averages of a w i d e
variety of c h e m i c a l species, including 0 3
and S 0 2 , w h i c h represent the v o l u m e
average for the grid cell. The version of
the model under e v a l u a t i o n is A D O M 2Bi
(Macdonald et al., 1 9 9 3 ) , w h i c h w a s run
for b o t h EMEFS intensive t i m e periods
using the observed m e t e o r o l o g y .
Model
results for J u l y 15 to A u g u s t 3 1 , 1 9 8 8
and M a r c h 25 t o April 3 0 , 1 9 9 0 are used
for the c o m p a r i s o n .
The m o d e l uses a single g r o u n d height
representative of the average t o p o g r a p h y
in the grid square. For the grid squares
considered here the g r o u n d height used for
the model is 4 1 6 m msl near M T and
a p p r o x i m a t e l y 4 7 0 m - m s l near RTR and
RTV.
In s o u t h e r n Quebec the actual
topography
w i t h i n a grid square
is
c o m p l e x , (e.g. the sites RTR and RTV are
separated
by about
10 km in the
horizontal, and 6 0 0 m in the vertical) and
the correct application of the o b s e r v a t i o n s
t o model e v a l u a t i o n is open t o s o m e
interpretation.
Two
scenarios
are
considered here. A c o m p a r i s o n is made
considering RTV t o be representative of
the l o w e s t layer of the model and RTR and
M T t o be representative of c o n d i t i o n s near
6 0 0 m-agl. This approach is f a v o u r e d by
the authors.
The CHEF data f r o m the m o u n t a i n t o p sites
w e r e c o m p a r e d w i t h layers f i v e and six of
the model (hereafter M 5 and M 6 ) , w h i c h
span 4 1 6 to 6 4 6 and 6 4 6 to 1 0 0 0 m-agl
respectively.
Data f r o m the valley site
w e r e c o m p a r e d w i t h layer one of the
model ( M 1 ) , w h i c h represents 1 t o 5 6 . 2
m-agl. M T is located near the centre of
grid square 1 9 , 2 0 . A p p r o x i m a t e l y 2 0 0 km
t o the s o u t h e a s t , the RTR and RTV sites
are centrally located on the n o r t h - s o u t h
border of grid squares 2 0 , 1 9 and 2 1 , 1 9 .
Data f r o m M T w e r e c o m p a r e d w i t h model
predictions for grid square 1 9 , 2 0 ( M T - M 5 ,
M T - M 6 ) and model results for grid squares
2 0 , 1 9 and 2 1 , 1 9 w e r e averaged (RT-M1,
R T - M 5 , RT-M6) to be c o m p a r e d w i t h the
data f r o m the Roundtop sites. It w i l l be
s h o w n t h a t the model predictions for
layers 5 and 6 are similar, and in general
w i l l not be distinguished f r o m each other in
the figures.
A second approach t o the evaluation of the
m o d e l , w h i c h considers b o t h RTV and RTR
t o be surface sites in the layer M 1 , w i l l be
discussed. In this case these t w o sites
represent the topographic e x t r e m e s for
sites located w i t h i n the grid square, and
the observations are bounds for conditions
in this layer.
The hourly-averaged observations w e r e
c o m p a r e d w i t h the model predictions b o t h
as f r e q u e n c y d i s t r i b u t i o n s and as scatterplots. Diurnal variability w a s established by
averaging the observations or model results
for each of the 2 4 hours in the day over the
entire s u m m e r or spring s t u d y period.
The ability of the model t o predict days
w i t h high or l o w 0 3 m i x i n g ratios w a s
assessed w i t h the True Skill Statistic (TSS)
(Flueck, 1987) as f o l l o w s . To allow the
t i m e trends t o be evaluated independently
of the absolute m i x i n g ratios seen,
daily-averaged predictions for each of
M T - M 5 , R T - M 5 and R T - M 1 , and data f r o m
M T , RTR and RTV w e r e ranked and tagged
as in the upper or l o w e r quartile for each
set (i.e. the t w o ranking schemes:
top
2 5 % or remaining 7 5 % ; b o t t o m 2 5 % or
remaining 7 5 % ) . Since, as w i l l be seen,
model layers 5 and 6 see the same t i m e
series of events, the observations and
model predictions w e r e related as M T w i t h
M T - M 5 , RTR w i t h RT-M5 and RTV w i t h
R T - M 1 . In addition, t o d i r e c t l y compare
the skill of the model w i t h the regionality of
the ozone events, observations of 0 3
m i x i n g ratio f r o m RTR w e r e used to
" p r e d i c t " c o n d i t i o n s at MTR and RTV. The
linkage b e t w e e n the model predictions for
the
grid
squares
of
interest
was
investigated by applying the TSS t o results
f r o m M T - M 5 and RT-M5.
The TSS is
based both on correct predictions (hits -e.g.
both
the
model
predicts
and
the
o b s e r v a t i o n s s h o w a day in the t o p 2 5 % )
and false predictions (misses - e.g. the
model predicts an upper quartile day but
the observations do not s h o w this t o be
true).
Values of the TSS of 1, 0 , and -1
indicate perfect predictive capability, no
predictive skill, and the w r o n g forecast
every t i m e , respectively.
Incorrectly
predicting 1 0 % , 4 0 % and 5 0 % of the t i m e
can g i v e TSS values near 0 . 8 , 0 . 2 and 0,
respectively.
RESULTS A N D DISCUSSION
Ozone
There is a marked d i f f e r e n c e in the
f r e q u e n c y d i s t r i b u t i o n s of the measured 0 3
hourly m i x i n g ratios seen in the s u m m e r
(Figure 1) and spring (Figure 2) intensive
periods. W h e r e a s in the spring period the
measured 0 3 m i x i n g ratios approach a
normal d i s t r i b u t i o n at all sites, w i t h a
w e l l - d e f i n e d peak at 4 5 to 5 0 ppbv for the
high elevation sites and at 35 t o 4 0 ppbv
for RTV, the distributions for the s u m m e r
period are substantially broadened and
s k e w e d t o l o w e r 0 3 m i x i n g ratios, peaking
at 2 0 t o 25 ppbv at M T , 3 0 t o 35 ppbv at
RTR, and 10 to 25 ppbv at RTV.
The
number of hours in w h i c h the m i x i n g ratio
of ozone exceeded the 1 hour Canadian
A m b i e n t Air Quality O b j e c t i v e of 8 2 ppbv
is small for all sites. The highest 0 3 m i x i n g
ratios are seen at M T in the s u m m e r w i t h 4
hours of data reaching 9 0 t o 128 ppbv.
C o n t r a r y t o the observations, the model
results, also s h o w n in Figures 1 and 2, are
s k e w e d t o w a r d higher 0 3 m i x i n g ratios in
the s u m m e r period, and do not reproduce
the l o w e r 0 3 m i x i n g ratios seen at t h a t
time.
For both periods, the modelled
d i s t r i b u t i o n s for the high elevation sites
appear
to
be
composites
of
two
d i s t r i b u t i o n s , one tending t o f o l l o w the
observations, and the second providing a
peak at l o w 0 3 m i x i n g ratios in the spring
and at high 0 3 m i x i n g ratios in the s u m m e r .
The closest agreement for the d i s t r i b u t i o n s
is seen b e t w e e n RTV and RT M 1 for the
spring season, w i t h the model results close
to normal, but slightly s k e w e d to l o w e r
m i x i n g ratios. The model predictions are
more
narrowly
distributed
than
the
observations in the s u m m e r for all sites,
and do not reproduce the tail at higher 0 3
m i x i n g ratios seen at the high elevation
sites in the spring.
O z o n e Mixing Ratio (pptr
Fig. 1
Frequency distributions for the hourly
ozone mixing ratios which were
measured (solid bars! and modelled
(hatched bars) for July 15 to
August 31, 1 988. Values for M5 and
M6 are shown for MT and RTR.
Since A D O M gives an average over a grid
cell it can be e x p e c t e d to be less variable
than m e a s u r e m e n t s made at a particular
site. This may explain the inability of the
model t o capture tails of the d i s t r i b u t i o n s
adequately.
However it is clear that the
model has consistent difficulty, o v e r d i s t a n c e
73
scales of 200 k m a n d a range of altitudes, in
predicting 0 3 mixing ratios greater than 70
ppbv for both seasons.
species. If the M T m e a s u r e m e n t s in t h e
spring ( s h o w n in Figure 2a) are assumed t o
be normally distributed, t h e n the e s t i m a t e d
error in that average is 0 . 3 p p b v .
TABLE 1
A v e r a g e O . mixing ratios (ppbv) for the s u m m e r 1 9 8 8 a n d
spring 1 9 9 0 periods. The standard d e v i a t i o n is s h o w n in
brockets.
number
of hours
Ozone Mixing Ratio (ppbv)
Fig. 2
Frequency distributions for the hourly
ozone mixing ratios which were
measured (solid bars) and modelled
(hatched bars) for March 25 to April
30, 1990. Values for M5 and M6 are
shown for MT and RTR.
Scatter
plots
relating
the
hourly
observations
at
RTR
with
model
predictions for R T - M 5 are s h o w n in Figure
3. Similar trends (not s h o w n ) are seen for
M 6 predictions for RTR and for M 5 and M 6
at M T .
In t h e s u m m e r the points are
generally clustered above the 1:1 line,
s h o w i n g model o v e r p r e d i c t i o n .
In the
spring the points fall generally below the
1:1 line, s h o w i n g model underprediction.
The relationships are not linear, but curve
at higher 0 3 m i x i n g ratios, w i t h the model
predicting l o w e r hourly m i x i n g ratios than
observed for b o t h t i m e periods.
Summer
50
100
M e a s u r e d Ozone (ppbv)
Fig. 3
S
P™9
50
100
Measured Ozone (ppbv)
Measured and modelled hourly 0 3
mixing ratios for RTR and RT-M5 for
the summer and spring intensive
periods. The 1:1 line is shown for
each plot.
The measured and modelled average hourly
0 3 m i x i n g ratios for the s u m m e r and spring
intensive periods for the three sites are
g i v e n in Table 1. Values calculated in the
same manner as standard deviations are
s h o w n for each average, even t h o u g h
s o m e of t h e d i s t r i b u t i o n s are far f r o m
normal (Figures 1 and 2). The large range
seen in the data does not indicate an
inability t o d e t e r m i n e the average precisely
due t o s o m e r a n d o m error, but rather
s h o w s the w i d e range of m i x i n g ratios
actually seen due t o the e f f e c t s of
d i f f e r e n t m e t e o r o l o g y on the c h e m i c a l
processing and transport of the pollutant
74
Physics in Canada
M arch/Aprill 9 9 6
observed
zone
— m o d e l l e d zone
Mb
M6
summer
MT
1147
RTR 1 0 3 2
RTV 1124
35
43
28
(16)
(16)
(17)
48
50
spring
MT
888
RTR 8 8 8
RTV 8 8 8
43
44
36
(9)
(10)
(9)
37
39
(11) 5 0
(10) 5 2
M1
(10)
(10)
3 2 (12)
(9)
(8)
39
41
(9)
(9)
32
(9)
The data in Table 1 s h o w that the largest
measured seasonal difference in average
0 3 m i x i n g ratio w a s seen at RTV and M T ,
w i t h 8 ppbv more 0 3 seen in t h e spring
period; a small d i f f e r e n c e of 1 ppbv w a s
seen at RTR.
Consistent w i t h earlier
observations (Schemenauer and A n l a u f ,
1987) a positive gradient is seen w i t h
elevation, and the more northerly M T site
tends t o have l o w e r s u m m e r t i m e 0 3 m i x i n g
ratios on average t h a n the RTR site. The
model o v e r p r e d i c t s the average ozone
m i x i n g ratio seen in the s u m m e r in M 5 and
M 6 by about 1 4 ppbv at M T , 8 ppbv at
RTR and 4 ppbv at RTV. For the spring
season the model underpredicts
the
average ozone m i x i n g ratio by about 5
ppbv at M T and 4 ppbv at RTR and RTV.
No seasonal difference is predicted for the
average 0 3 m i x i n g ratio for RTV.
The
model does s h o w a positive gradient w i t h
elevation, and lower m i x i n g ratios at M T .
The mean diurnal variation in 0 3 m i x i n g
ratio for the m e a s u r e m e n t s and model
results is s h o w n in Figure 4. The model
o v e r p r e d i c t i o n in the s u m m e r period and
underprediction in the spring period can be
seen t o be quite u n i f o r m t h r o u g h o u t the
day at the high elevation sites.
The
summer
data
at
RTV
show
good
agreement w i t h the model predictions in
the late afternoon. The observed ozone
m i x i n g ratios for the high altitude sites
s h o w the m a x i m a for the diurnal cycle
o c c u r r i n g near 2 UTC and 21 t o 2 3 UTC
for the s u m m e r and spring periods,
respectively, and the minima occurring
near 14 UTC and 15 t o 19 UTC in the
s u m m e r and spring periods, respectively.
The amplitude of the diurnal variation at
M T is 9 . 7 and 4 . 8 ppbv in the s u m m e r and
spring
periods,
respectively.
The
amplitudes seen at RTR are about half a
ppbv smaller. The predicted M 5 and M 6
ozone m i x i n g ratios for the high altitude
sites s h o w the diurnal cycle occurring w i t h
a p p r o x i m a t e l y the same t i m i n g , but w i t h
smaller
amplitude
in
the
summer
( a p p r o x i m a t e l y 2 ppbv) and at M T in the
spring ( 2 . 4 ppbv).
The t i m i n g of the
observed and predicted diurnal variation at
RTV agrees w e l l , w i t h the m a x i m a near 18
UTC and 21 UTC in the s u m m e r and spring
periods, respectively, and the minima near
10 UTC. The amplitude of the signal at
RTV is measured t o be 2 1 . 6 ppbv in the
s u m m e r period, c o m p a r e d w i t h a predicted
value of 1 6 . 4 ppbv.
The agreement is
better in the spring period, w i t h a
measured
amplitude
of
11.8
ppbv
c o m p a r e d w i t h a predicted 1 0 . 6 p p b v .
Since the m i n i m a at the high elevation
sites do not occur at night it is clear that
these sites are not under the influence of
the nocturnal inversion in the same w a y as
RTV, but instead are under the influence of
tropospheric air continually t r a n s p o r t e d t o
the site.
It is possible that the diurnal
m i n i m u m observed at M T and RTR is due
t o 0 3 - d e p l e t e d air f r o m below the nocturnal
inversion m i x i n g up f r o m the surface in
response t o surface heating.
This
mechanism would
lead t o a larger
amplitude in the s u m m e r , as observed at
all sites, because d e p o s i t i o n t o the
v e g e t a t i o n at the surface is stronger during
the nocturnal inversion in the s u m m e r t h a n
t o the s n o w covered surface in t h e spring.
This is consistent w i t h RTV, w h i c h s h o w s
the strongest a f t e r n o o n peak and the
sharpest decline at night, being b e l o w the
nocturnal inversion w h i l e RTR and M T are
above. This diurnal behavior of the high
elevation sites supports the use of data
f r o m these sites t o evaluate the model in
elevated layers.
Hour (UTC)
Fig. 4 Diurnally averaged 0 3 mixing ratio for
MT (top panel), RTR (middle panel) and
RTV (lower panel).
Local Eastern
Standard time is given by UTC - 5 hours.
The lateral boundary conditions for the
model
(Michael
Moran,
personal
c o m m u n i c a t i o n ) for the s u m m e r period for
0 3 w e r e m i x i n g ratios of 4 1 . 9 , 6 0 . 2 and
6 1 . 9 ppbv for layers 1, 5 and 6,
respectively, along the w e s t e r n grid
boundary and 3 1 . 2 , 3 2 . 8 and 3 3 . 7 ppbv
for layers 1, 5 and 6, respectively, for the
northern and eastern boundaries, and m o s t
of the s o u t h e r n boundary.
Three grid
squares in the s o u t h e r n boundary, those
over Florida, w e r e g i v e n the
same
conditions as the w e s t e r n boundary. The
lateral boundary conditions for the spring
period w e r e 0 3 m i x i n g ratios of 4 4 . 9 , 4 4 . 1
and 4 5 . 3 ppbv for layers 1, 5 and 6,
respectively, along the boundaries in the
s o u t h w e s t e r n corner and 3 0 . 1 , 3 1 . 6 and
3 2 . 5 ppbv for layers 1, 5 and 6,
respectively,
for
the
northwestern,
northern,
eastern
and
southeastern
boundaries. Figures 1 and 2 s h o w that the
predicted model m i x i n g ratios in layers 5
and 6 have a peak w i t h i n the range defined
by the boundary c o n d i t i o n s for each
season.
This c o m p a r i s o n suggests that
for m u c h of the t i m e the ozone modelled
for M 5 and M 6 at these locations s i m p l y
reflects transport and m i x i n g of the ozone
w h i c h w a s input as a boundary c o n d i t i o n
at that layer. If this is indeed the case
t h e n the o b s e r v a t i o n s indicate that l o w e r
input c o n c e n t r a t i o n s should be specified in
the s u m m e r season, and higher in the
spring t h a n c u r r e n t l y in use, and the
sensitivity of the model results t o the
choice of boundary c o n d i t i o n s should be
investigated.
predicted values lie at l o w e r m i x i n g ratios
t h a n the observations. Higher variability,
on a daily averaged basis, is seen for 0 3 in
the s u m m e r period t h a n in the spring
period. The TSS test of t i m e trends of
measured values and model predictions for
all sites is s h o w n in Table 2. The model
shows
its
highest
success
(TSS
a p p r o x i m a t e l y 0 . 7 7 ) in predicting periods
w i t h l o w ozone m i x i n g ratio at both RTR
and M T in the s u m m e r , w i t h the next
highest success (TSS of 0 . 6 7 ) for l o w
ozone periods at RTV in the s u m m e r . The
upper quartile d a y s are predicted w i t h a
TSS of at least 0 . 5 6 for MT and RTR over
both periods. The poorest p e r f o r m a n c e is
seen for RTV in the spring.
A n o t h e r f a c t o r w h i c h could c o n t r i b u t e t o
the o v e r p r e d i c t i o n of 0 3 m i x i n g ratios in
the
summer
period
is
model
u n d e r e s t i m a t i o n of the 0 3 d e s t r u c t i o n at
night at l o w elevations. U n f o r t u n a t e l y it
is not clear if the d i f f e r e n c e seen at night
b e t w e e n the average measured
and
modelled m i x i n g ratios in the s u m m e r in
layer 1 is due to the model u n d e r e s t i m a t i n g
the losses in the n o c t u r n a l boundary layer
or to the limited vertical resolution of the
model (Byun and Dennis, 1 9 9 5 ) .
In
addition, the w e a k m i x i n g in the l o w e r
layers of the m o d e l as suggested by
c o m p a r i s o n of the diurnal v a r i a t i o n at
higher layers, w o u l d c o n t r i b u t e to the
transport of 0 3 m i x i n g ratios characteristic
of the initial boundary c o n d i t i o n s .
The TSS
indicates
thaï
the
model
d e m o n s t r a t e s a strong regionality in ozone
episodes in layer 5, w i t h a TSS > 0 . 8 for
b o t h seasons for l o w ozone and a TSS
near 0 . 7 for high ozone w i t h results for
RT-M5 used t o predict M T - M 5 . The TSS
supports the use of data f r o m M T and RTR
as representative of regional scale ozone
episodes since RTR can " p r e d i c t " the
conditions at M T on a large f r a c t i o n of
days (TSS range b e t w e e n 0 . 5 6 and 0 . 7 6 ) .
These applications of the TSS give a
standard
by
which
to
judge
the
p e r f o r m a n c e of the model for the high
elevation sites. In general the model can
predict the t i m i n g of periods w i t h high and
l o w ozone as observed at the high
elevation sites over distances of 2 0 0 k m .
The interpretation of the TSS for daily
averages at RTR and RTV is c o m p l i c a t e d
by the fact t h a t the valley site is subject to
the stronger diurnal variation.
predicted d i s t r i b u t i o n for the first layer.
The s u m m e r average m i x i n g ratio in the
l o w e s t layer could be reproduced by a
suitable averaging of the RTV and RTR
data, but any such averaging for the spring
season
would
still
lead
to
an
underprediction.
(a)
§f
100
m
S 0 2 Mixing Ratio (ppbv)
(b)
Measured S 0 2 Mixing Ratio (ppbv)
TABLE 2
T r u e Skill Statistic c a l c u l a t e d o n 4 8 d a y s of d a t a for M T a n d
R T V , a n d 4 4 d a y s of d a t a for RTR in the s u m m e r a n d 3 7
d a y s of d a t a for all sites in the spring for the l o w e r (L) a n d
upper (H) quartiles of d a t a .
Summer L
Fig. 5
19 Aug
26-Aug
Spring H
0.76
0.64
0.56
0.56
MT-M5
to^wedict
0.78
0.56
0.41
0.56
RT-M1
to predict
RTV
0.67
0.44
0.27
0.27
0.76
0.64
0.56
0.71
0.52
0.76
0.56
0.27
RTR
to predict
RTV
12-Aug
Spring L
RT-M5
to p r e d i c t
RTR
RTR
to p r e d i c t
S-Aug
Summer H
2-Sep
Ozone data for the summer intensive
period showing measured (solid
symbol, solid line) and modelled (open
symbol, dashed line) daily averages.
Both M5 and M6 are shown for for
MT and RTR.
Time series of the measured and modelled
daily averages of 0 3 m i x i n g ratio are
s h o w n in Figure 5 for the s u m m e r
intensive period. The regional nature of
the ozone e v e n t s can be seen by
c o m p a r i n g the measured c u r v e s f r o m the
d i f f e r e n t sites. The trends w i t h t i m e for
the measured and predicted daily-averaged
ozone m i x i n g ratios for the spring period
(not s h o w n ) are similar t o those s h o w n in
Figure 5 w i t h the e x c e p t i o n that the
RT-M5
to predict
MT-M5
If RTR and RTV are b o t h considered as
sites in M 1 the f o l l o w i n g conclusions
reached above w i l l still be valid.
Any
c o m b i n a t i o n of the d i s t r i b u t i o n s observed
during the s u m m e r period at RTR and RTV
w i l l lead t o a d i s t r i b u t i o n that indicates
more hours w i t h 0 3 m i x i n g ratio above 6 0
ppbv t h a n does the predicted d i s t r i b u t i o n
RT-M1.
Any
combination
of
the
d i s t r i b u t i o n s observed at these sites in the
spring w i l l lead t o a d i s t r i b u t i o n w h i c h
peaks at higher 0 3 m i x i n g ratios than the
Fig. 6 Observations and model results for SO?
mixing ratios at RTR during the spring
period:
a) frequency distribution of
measured (solid) and modelled (hatched)
hourly data, bl scatter plot of hourly
data with RT-M5 results, c) time series
of measured hourly averages (dashed
line), measured daily averages (solid
symbol/line), and modelled daily averages
(open symbol/line) and d)
diurnally
averaged measurements (solid symbols)
and model results (open symbols). The
results for both RT-M5 and RT-M6 are
shown for all plots except b) which
shows RT-M5 only.
Sulphur Dioxide
The d i s t r i b u t i o n of measured S 0 2 m i x i n g
75
ratios in the spring period is s k e w e d , w i t h
the m o d e in the range 0 t o 0 . 5 ppbv, over
half t h e data w i t h i n 1 ppbv of zero, and
m a x i m u m values reaching 8 ppbv (Figure
6a). The small negative values are due t o
variability in t h e zero c o r r e c t i o n .
The
d i s t r i b u t i o n for the A D O M predictions, also
shown
in
Figure
6a,
is
a
good
representation
of
the
measurements.
H o w e v e r , an hour by hour c o m p a r i s o n of
the o b s e r v a t i o n s and M 5 results (Figure
6b) s h o w s considerable scatter. Results
for M 6 are similar.
The t i m e series of daily averages of
measured and modelled S 0 2 m i x i n g ratio
(Figure 6c) s h o w s periods w i t h v e r y g o o d
a g r e e m e n t , as w e l l as p e r i o d s w i t h
o v e r p r e d i c t i o n and underprediction.
The
TSS indicates poor predictive capability for
the model w i t h values of 0 . 2 7 for the upper
quartile d a y s and 0 . 1 2 for t h e l o w e r quartile
days.
The average S 0 2 m i x i n g ratios over the
f i v e w e e k period w e r e 1 . 2 9 , 1 . 2 9 and
1 . 2 5 ppbv for t h e measured, M 5 and M 6
values r e s p e c t i v e l y , s h o w i n g excellent
a g r e e m e n t . The diurnal v a r i a t i o n in S 0 2
m i x i n g ratio (Figure 6d) has an amplitude
of 0 . 5 p p b v , and a m a x i m u m near 1 4 UTC
in
both
the
model
results
and
m e a s u r m e n t s , indicating t h a t on average in
the spring season S 0 2 , as 0 3 ,
is
appropriately m i x e d t h r o u g h t h e l o w e r
troposphere.
The above observations indicate that the
e m i s s i o n of t h e p r i m a r y pollutant S 0 2 and
its subsequent transport t o s o u t h e r n
Quebec are w e l l represented by A D O M over
the full spring period.
H o w e v e r , the
predicted t i m i n g of episodes of high S 0 2 is
poor b o t h on an hourly and daily basis. This
is not surprising since, unlike 0 3 w h i c h is
gradually produced f r o m a c o m p l e x mix of
pollutants in t h e l o w e r troposphere, S 0 2 is
introduced into t h e a t m o s p h e r e at elevated
levels f r o m a v a r i e t y of point sources t o the
s o u t h and w e s t of t h e sites. Small s h i f t s in
w i n d d i r e c t i o n or changes in vertical
stability of t h e a t m o s p h e r e relative t o the
model resolution can cause the plumes t o
hit or miss t h e g r i d cells being evaluated.
There
is no
observational
evidence
presented here t o indicate that t h e S 0 2
episodes seen at RTR on an hourly or daily
basis are routinely representative, o n these
t i m e scales, of c o n d i t i o n s over the entire
g r i d cell.
Additional
High
Measurements
Elevation
Ozone
The results f r o m the CHEF sites can be
compared
with
results
of
ozone
m e a s u r e m e n t s at high elevation sites in the
eastern U.S.
Aneja and Li ( 1 9 9 2 ) s h o w
diurnal variations at W h i t e f a c e M o u n t a i n ,
N . Y . ( 1 4 8 3 m - m s l ) and M t . Moosilauke,
N.H. ( 1 0 0 0 m-msl).
In the s u m m e r of
1 9 8 8 ( M a y t o October) b o t h sites s h o w
m i n i m a f r o m about 0 9 0 0 t o 1 2 0 0 local
t i m e and broad m a x i m a e x t e n d i n g f r o m
about 1 8 0 0 t o 2 4 0 0 . This is v e r y similar
t o t h e diurnal patterns s h o w n in Figure 4
for the t w o CHEF m o u n t a i n sites during
t h e A D O M period. These diurnal patterns
are c o n s i s t e n t w i t h w h a t other authors
76
Physics in Canada
M arch/Aprill 9 9 6
have reported for high elevation sites, e.g.,
Lefohn et al. ( 1 9 9 0 ) for
Whiteface
M o u n t a i n and Aneja et al. ( 1 9 9 4 ) for t w o
elevations ( 2 0 0 6 and 1 7 6 0 m-msl) in N o r t h
Carolina. Aneja and Li ( 1 9 9 2 ) report the
A u g u s t 1 9 8 8 W h i t e f a c e M o u n t a i n mean
ozone c o n c e n t r a t i o n t o be 5 0 . 3 ppbv. This
is similar t o , but higher t h a n , the value
g i v e n for the A D O M period for the CHEF
RTR site in Table 1 (43 ppbv). W h i t e f a c e
M o u n t a i n is 1 4 0 k m s o u t h w e s t of RTR and
at an elevation 6 3 0 m higher. In general,
w h e r e c o m p a r i s o n s can be made, and
considering the general s o u t h t o north
decrease in ozone c o n c e n t r a t i o n s
in
eastern N o r t h A m e r i c a , the measured
ozone c o n c e n t r a t i o n s at the t w o CHEF
m o u n t a i n sites seem representative of
values t o be e x p e c t e d at 8 5 0 m - m s l and
should provide a good basis for c o m p a r i s o n
w i t h the A D O M model.
C o m p a r i s o n of M o d e l Evaluations
The results for the s u m m e r period g i v e n
above agree w e l l w i t h conclusions d r a w n
for model intercomparisons for the same
time
period
for
southern
Ontario.
M a c d o n a l d et al. ( 1 9 9 3 ) concluded that
the model can predict the t i m i n g of
episodes in the l o w e r troposphere ( 2 5 0 t o
2 2 0 0 m-agl), that the full range of
observed 0 3 m i x i n g ratios w a s not seen by
t h e model, and that the observed vertical
m i x i n g of pollutants w a s underpredicted by
the model. Hoff et al. ( 1 9 9 5 ) concluded
t h a t A D O M treats the t e m p o r a l behaviour
of 0 3 fairly w e l l in the l o w e r troposphere
but not near the surface, t h a t the model
p e r f o r m s best during simple s y n o p t i c
conditions
with
a
relatively
clean
a t m o s p h e r e , and t h a t local c h e m i s t r y
appears t o be secondary t o larger-scale
dynamic
motions
through
the
free
troposphere in controlling the average
ozone c o n c e n t r a t i o n .
The data and
m e t h o d used for t h e evaluation g i v e n in
this paper permit more sensitive and
q u a n t i t a t i v e testing of the model in layers
5 and 6, and w i l l be appropriate for
evaluating the e f f e c t of proposed changes
t o the model.
CONCLUSIONS
The application of the True Skill Statistic
t o the ozone m e a s u r e m e n t s at the high
elevation sites c o n f i r m s that periods of
high and l o w ozone m i x i n g ratio occur over
d i s t a n c e scales of 2 0 0 k m in s o u t h e r n
Quebec. C o m p a r i s o n of the ozone data
f r o m the Canadian sites w i t h results f r o m
other m o u n t a i n observations in eastern
N o r t h A m e r i c a s h o w decreasing ozone
c o n c e n t r a t i o n s w i t h increasing latitude.
These long t e r m measurement programs
can
supply
valuable
continuous
m e a s u r e m e n t s for the evaluation of air
c h e m i s t r y models.
observed values in b o t h seasons, and
w h i c h give higher m i x i n g ratios on average
in the s u m m e r t h a n in the spring. Thus the
seasonal dependence of the 0 3 m i x i n g ratio
is d i f f e r e n t for t h e model and the
observations.
This d i f f e r e n c e m a y be
related t o
the choice
of
boundary
conditions, and t o u n d e r e s t i m a t i o n of the
depletion of 0 3 near the surface at night in
the s u m m e r .
The A D O M m i x i n g ratios for b o t h t h e
s u m m e r and spring t i m e periods v e r y rarely
exceed 6 0 ppbv and are never greater t h a n
7 0 ppbv w h e r e a s the m e a s u r e m e n t s reach
and exceed 9 0 ppbv at t i m e s . Thus t h e
model cannot reproduce the m a g n i t u d e of
events w i t h high 0 3 m i x i n g ratio.
The prediction of the t i m i n g of e v e n t s is
often
evaluated
simply
by
visual
inspection, w h i c h tends t o fix the eye on
the major peaks in the t i m e series,
especially if agreement is f o u n d b e t w e e n
the observations and predictions for these
peaks.
The application of an o b j e c t i v e
numerical measure of agreement, s u c h as
the True Skill Statistic, is r e c o m m e n d e d .
For the t i m e s investigated here, it is s h o w n
that the model has the greatest skill in
predicting the t i m i n g of l o w ozone periods
at the high elevation sites.
The measured and modelled
diurnal
variations in 0 3 are similar in the t i m i n g of
the m a x i m a and m i n i m a , indicating that t h e
m i x i n g in the boundary layer is occurring at
the right t i m e of d a y , and depletion of
ozone is occurring in the
nocturnal
inversion.
However
the
difference
b e t w e e n the m a x i m a and m i n i m a in the
predicted values are l o w e r t h a n in the
observed values for the s u m m e r period for
b o t h high elevation sites and in t h e spring
at M T , indicating that the model t r e a t m e n t
of boundary layer m i x i n g m a y not be
strong enough. This w o u l d be especially
evident in s u m m e r w h e n increased surface
losses are seen in the nocturnal boundary
layer. M i x i n g t o higher layers is i m p o r t a n t
since it a f f e c t s not only t h e c o n c e n t r a t i o n s
at that layer, but the long range transport
of species due t o the higher w i n d speeds
aloft.
The m i x i n g ratios of S 0 2 at RTR during the
spring period range f r o m near zero t o
a p p r o x i m a t e l y 10 ppbv in w e l l - d e f i n e d
events.
The d i s t r i b u t i o n of hourly S 0 2
m i x i n g ratios for the model results and
m e a s u r e m e n t s agree w e l l , but the model
s h o w s poor skill in predicting the t i m i n g of
episodes. The diurnal variation in S 0 2 is
w e l l represented by the model, c o n s i s t e n t
w i t h the g o o d agreement seen for 0 3 at
RTR for this t i m e period.
ACKNOWLEDGEMENTS
The distributions of 0 3 m i x i n g ratios
observed for the s u m m e r 1 9 8 8 and spring
1990
EMEFS
intensive
periods
are
d i f f e r e n t , w i t h a smaller range of values
seen in the spring t h a n in the s u m m e r and
w i t h higher average 0 3 m i x i n g ratio seen in
t h e spring t h a n in the s u m m e r . The A D O M
predicts distributions of 0 3 m i x i n g ratios
w h i c h span a smaller range t h a n the
W e thank Francine Juillet, Louis V e i l l e u x ,
Alaine Dufresne, S y l v a i n Savoie and
Nicolas Durand for operating t h e CHEF
sites, and Sheldon Opps for assistance in
data processing.
(continued on page 8 0 )
C O N T R Ô L E DES M O D E S L A T É R A U X DE L A S E R S À S E M I C O N D U C T E U R S :
E X P É R I E N C E S ET S I M U L A T I O N S
par
Nathalie M c C a r t h y , S y l v a i n M a i l h o t , Damien S t r y c k m a n , Yves C h a m p a g n e * et Guy Rousseau
Équipe Laser et Optique Guidée, Centre d ' O p t i q u e , Photonique et Laser (COPL), Département de physique, Université Laval,
Québec, G1 K 7P4, Canada, Tél.: (418) 6 5 6 - 3 1 2 0 , Fax: (418) 6 5 6 - 2 6 2 3 , e-mail: n m c c a r @ p h y . u l a v a l . c a
* Gentec Inc. 2 6 2 5 Dalton, Sainte-Foy, Québec, G1P 3S9, Canada
Résumé
Les
lasers
à
semi-conducteurs
de
puissance
élevée,
à
large
fenêtre
d ' é m i s s i o n , sont d e v e n u s des sources
cohérentes
très
compétitives
pour
plusieurs applications.
Cependant, ces
lasers
émettent
simultanément
sur
plusieurs modes latéraux, ce qui a u g m e n t e
la d i v e r g e n c e du faisceau et en d i m i n u e la
cohérence spatiale. Notre but consiste à
réduire le n o m b r e de modes latéraux
c o n t e n u s dans le faisceau émis par ce t y p e
de lasers disponibles c o m m e r c i a l e m e n t .
Quelques techniques de c o n t r ô l e de modes
latéraux ont été proposées et testées avec
des lasers de 1 0 0 m W : c a v i t é s externes
terminées
par d i f f é r e n t s
composants
optiques et c o u c h e s à r é f l e c t i v i t é profilée
déposées d i r e c t e m e n t sur la face de sortie
des lasers.
Nous présentons aussi les
résultats de simulations numériques reliées
aux expériences réalisées.
Abstract
High p o w e r broad-area (BA) s e m i c o n d u c t o r
lasers are n o w considered as interesting
sources of coherent radiation for various
applications. H o w e v e r these lasers emit
s i m u l t a n e o u s l y on several lateral m o d e s ,
w h i c h c o n t r i b u t e t o increase the beam
divergence and t o decrease the spatial
coherence of the e m i t t e d laser beam. Our
goal c o n s i s t s in reducing the number of
lateral modes contained in the beam
e m i t t e d by c o m m e r c i a l l y available BA
lasers. Some techniques of lateral mode
c o n t r o l have been proposed and t e s t e d
w i t h a 1 0 0 m W BA laser: external cavities
t e r m i n a t e d by various optical c o m p o n e n t s
and profiled r e f l e c t i v i t y c o a t i n g s deposited
d i r e c t l y on the o u t p u t f a c e t of the lasers.
Numerical s i m u l a t i o n s of the lateral m o d e
d i s c r i m i n a t i o n of these c o n f i g u r a t i o n s are
also reported.
INTRODUCTION
Les lasers à s e m i - c o n d u c t e u r s (ou diodes
laser) de puissance élevée ont atteint des
niveaux de p e r f o r m a n c e qui en f o n t des
sources cohérentes c o m p é t i t i v e s pour une
v a s t e g a m m e d ' a p p l i c a t i o n s : mémoires
optiques,
génération
d'harmoniques,
s y s t è m e s de c o m m u n i c a t i o n optique et
pompage optique de lasers à l'état solide.
O n divise habituellement les diodes laser
de puissance en deux grandes catégories,
soient les réseaux m o n o l i t h i q u e s de diodes
laser et les lasers à large ruban d ' i n j e c t i o n
("broad-area" ou BA). De f a ç o n générale,
les réseaux de diodes laser présentent une
bonne d i s c r i m i n a t i o n envers les modes
latéraux (suivant l ' a x e x , dans le plan de la
jonction) d ' o r d r e supérieur, mais leur m o d e
fondamental
se
caractérise
par
un
déphasage de 180° entre les é m e t t e u r s
adjacents, ce qui produit une d i s t r i b u t i o n
angulaire d ' i n t e n s i t é à deux lobes dans le
c h a m p lointain. D ' a u t r e part, les lasers BA
ont une faible d i s c r i m i n a t i o n entre les
modes latéraux et tendent à é m e t t r e
s i m u l t a n é m e n t sur plusieurs modes.
La
présence de ces modes d ' o r d r e supérieur
est à l'origine d ' u n e f o r t e dégradation de la
cohérence spatiale du faisceau et d ' u n e
d i s t r i b u t i o n d ' i n t e n s i t é en c h a m p lointain
qui s'élargit rapidement lorsque le courant
d ' i n j e c t i o n a u g m e n t e . Ces c o m p o r t e m e n t s
sont très néfastes l o r s q u ' o n v e u t , par
e x e m p l e , utiliser le faisceau pour pomper
o p t i q u e m e n t un autre laser: le faisceau doit
plutôt être focalisable sur une petite tache
t o u t en restant étroit sur une grande
distance le long de l ' a x e de propagation z,
c e t t e d i s t a n c e étant optimale lorsque le
faisceau ne contient que le m o d e latéral
gaussien.
Dans
cet
article,
nous
présentons
d i f f é r e n t e s m é t h o d e s que nous avons
utilisées pour réduire le n o m b r e de modes
latéraux dans les diodes laser BA t o u t en
c o n s e r v a n t une puissance relativement
élevée:
les
cavités
externes
anamorphiques, les cavités à s y m é t r i e
cylindrique
terminées
par
différents
c o m p o s a n t s optiques (miroir u n i f o r m e ,
miroir à réflectivité profilée...) et les
c o u c h e s à réflectivité profilée déposées
d i r e c t e m e n t sur la face de sortie (face
d'émission)
des diodes
laser.
Les
techniques de d é p o s i t i o n sont brièvement
décrites.
Les résultats de simulations
numériques
reliées
aux
travaux
e x p é r i m e n t a u x sont aussi présentés.
C A V I T É S EXTERNES
Les cavités externes (ou cavités étendues)
ont déjà fait leurs preuves pour le contrôle
des modes l a t é r a u x . " 3 1
Les cavités
externes o f f r e n t plusieurs degrés de liberté
p u i s q u ' o n peut varier le nombre et le t y p e
de c o m p o s a n t s i n t r a c a v i t é s , de m ê m e que
le t y p e de coupleur externe. La figure 1
m o n t r e le schéma du m o n t a g e que nous
avons utilisé pour mesurer les principales
caractéristiques d ' é m i s s i o n de la diode
laser en c a v i t é externe.
t e r m i n e la cavité. La f a b r i c a t i o n de ces
c o u c h e s anti-réfléchissantes est décrite
plus loin dans c e t t e section. La lentille f,
collimate le faisceau qui est ensuite
focalisé par la lentille F sur la fente
d ' e n t r é e d ' u n s p e c t r o m è t r e à réseau
(Jarrell A s h , résolution = 0 . 0 1 nm) à la
sortie
duquel
une
caméra
CCD
m o n o c h r o m e (Spiricon) enregistre l'image
du c h a m p proche du faisceau résolu en
longueur d ' o n d e . Le laser a été positionné
de f a ç o n à ce que la j o n c t i o n (et par
conséquent
l'axe
latéral)
soit
perpendiculaire au plan de la figure 1. Pour
travailler dans des conditions de cavité
externe anamorphique, nous ajoutons une
lentille cylindrique f 2 (de 25 m m de focale)
entre f, et M , ; c e t t e nouvelle lentille
n ' a y a n t un effet que le long de l'axe latéral
x.
A f i n d'alléger l ' é c r i t u r e , nous désignerons
par la lettre A la c o n f i g u r a t i o n pour laquelle
la lentille f 2 et le miroir M , sont absents du
m o n t a g e . Dans ce cas, nous avons fait les
mesures avant de déposer une couche AR
sur la face de sortie du laser.
La
c o n f i g u r a t i o n B sera celle qui c o m p o r t e une
cavité externe anamorphique 1 4 1 . Dans ce
cas, M , est un miroir plan à réflectivité
u n i f o r m e (R = 3 0 % ) , la distance L, entre
le laser et la lentille f, est de 8 m m et f,
possède une focale de 8 m m . La distance
L 2 entre M , et la lentille cylindrique f 2 peut
être variée alors que la distance d entre f,
et f 2 est gardée fixe à 3 0 m m . Le grand
intérêt de c e t t e c o n f i g u r a t i o n réside dans le
fait que la taille de la d i s t r i b u t i o n
transverse d ' i n t e n s i t é (dans la d i r e c t i o n y)
du faisceau à la face de sortie du laser est
la m ê m e après son trajet dans la cavité
externe.
Ceci permet d ' o p t i m i s e r le
couplage transverse entre le faisceau et le
guide d ' o n d e du laser. Dans la d i r e c t i o n
latérale
(direction
x),
on
recherche
e x a c t e m e n t le c o m p o r t e m e n t inverse: le
faisceau qui revient dans le laser s ' e s t
élargi pendant son trajet dans la cavité
externe et c ' e s t le milieu de gain lui-même
qui agit c o m m e filtre spatial profilé,
f a v o r i s a n t ainsi la présence des modes
latéraux les plus étroits. Finalement, la
c o n f i g u r a t i o n C ne c o m p r e n d que la lentille
de c o l l i m a t i o n f, et un miroir M , dont la
r é f l e c t i v i t é varie de f a ç o n gaussienne avec
le rayon 161 La f o r m e e x a c t e du profil de
réflectivité est donnée par
R(p) = 0 . 6 2 exp[-(p / w j ? | ,
Figure 1. Schéma du montage expérimental de
la diode laser en cavité externe et de
l'arrangement utilisé pour l'analysede
son faisceau.
La face arrière du laser a une réflectivité
élevée (R ~ 1 0 0 % ) . L'autre face (face
avant) a été recouverte d ' u n e c o u c h e
anti-réfléchissante
(AR)
afin
que
l'oscillation laser puisse s'établir entre la
face arrière et le miroir externe M 1 qui
où p est la position radiale et w m (la
demi-largeur à 1/e) est égale à 7 0 0 L e
profil de r é f l e c t i v i t é est
obtenu
en
déposant
des
couches
profilées
de
diélectriques sur un substrat de verre. Il a
été réalisé par l ' I n s t i t u t national d ' o p t i q u e
(Québec).
Dans t o u t e s les c o n f i g u r a t i o n s , les lasers à
s e m i - c o n d u c t e u r s utilisés sont des lasers
77
EG&G
de
GaAs/GaAIAs
(modèle
C 8 6 0 9 0 E ) , à double h é t é r o s t r u c t u r e , avec
une largeur de ruban de 75 f j m et une
longueur de 3 7 0 / / m .
Ils é m e t t e n t un
faisceau de puissance m a x i m a l e de l'ordre
de 1 0 0 m W , à une longueur d ' o n d e de 8 4 0
n m et leur c o u r a n t de seuil se situe entre
2 2 0 et 2 5 0 m A avant le t r a i t e m e n t
anti-réfléchissant. Le faible c o n f i n e m e n t
latéral du faisceau lumineux se propageant
dans le m a t é r i a u s e m i - c o n d u c t e u r est
assuré u n i q u e m e n t par un m é c a n i s m e de
"guidage par le g a i n " . L ' é m i s s i o n de telles
diodes
laser
contient
habituellement
plusieurs modes latéraux, m ê m e à des
puissances très faibles (de l'ordre du
milliwatt).
Par e x e m p l e , nous avons
d é t e c t é , avec u n de nos lasers,
la
présence de 3 modes latéraux à 2 . 5 m W et
de 1 1 modes
latéraux à 8 0 m W de
puissance émise. Sur les lasers destinés à
être utilisés en c a v i t é e x t e r n e , nous
d é p o s o n s une couche anti-réfléchissante
sur la face de sortie par évaporation
thermique.
Dans le s y s t è m e à vide, le
faisceau émis par la diode laser est d é t e c t é
pendant que le d é p ô t de SiO s ' e f f e c t u e ;
l ' é v a p o r a t i o n est arrêtée lorsque le signal
d é t e c t é atteint un m i n i m u m .
Nous
pouvons
estimer
que
la
réflectivité
résiduelle de la face est inférieure à 1 0 4
après le t r a i t e m e n t anti-réfléchissant.
Les figures 2a, 2b et 2c m o n t r e n t les
images du faisceau en c h a m p proche
résolu en longueur d ' o n d e obtenues avec la
diode laser dans les c o n f i g u r a t i o n s A , B et
C respectivement.
m
identifiés par leur longueur d ' o n d e plus
courte
et
leur
distribution
spatiale
d ' i n t e n s i t é à plusieurs lobes.
On peut
constater aussi que le m o d e latéral
f o n d a m e n t a l (à un seul lobe) est beaucoup
plus étroit sur la face de sortie que les
modes latéraux supérieurs. La figure 2a a
été enregistrée à une puissance de 3 2 m W .
Pour ce laser, on constate que sept modes
latéraux étaient présents à c e t t e puissance.
La figure 2b a été obtenue avec la cavité
externe anamorphique pour laquelle L 2
était de 1 0 0 m m .
On c o n s t a t e que
l ' é m i s s i o n est à la fois m o n o m o d e latérale
et
monomode
longitudinale
(résultat
c o n f i r m é par d ' a u t r e s mesures: a u c u n
b a t t e m e n t de mode n'a été observé) à une
puissance de 4 0 m W .
Ceci représente
notre meilleur résultat j u s q u ' à présent. La
figure 2c m o n t r e le spectre o b t e n u avec un
miroir gaussien externe pour une puissance
de 4 7 m W . L'écart entre les groupes de
modes longitudinaux est encore de 0 . 2 nm.
Dans ce cas, on observe un phénomène
particulier: le c o n t e n u en modes latéraux à
l'intérieur des groupes associés à des
modes longitudinaux d i f f é r e n t s n ' e s t pas le
m ê m e d ' u n groupe à l'autre. D ' u n e part, il
aurait été préférable que le profil de
réflectivité
ait
été
plus
étroit
afin
d ' a u g m e n t e r encore plus les pertes des
modes latéraux supérieurs. D ' a u t r e part, la
r é f l e c t i v i t é résiduelle du revêtement AR
pourrait être à l'origine d ' u n e f f e t de
c a v i t é s couplées.
La c o n f i g u r a t i o n qui nous a donné les
meilleurs résultats est la c a v i t é externe
anamorphique; dans ce cas, le paramètre
que nous avons fait varier est la distance
L 2 entre la lentille f 2 et le miroir externe
M , . Les cercles de la figure 3 m o n t r e n t le
courant de seuil mesuré e x p é r i m e n t a l e m e n t
de l ' é m i s s i o n laser (ceci correspond au
seuil
d'oscillation
du
mode
latéral
f o n d a m e n t a l , d ' o r d r e 0), alors que les
carrés m o n t r e n t le seuil mesuré du m o d e
d ' o r d r e 1 (ceci correspond donc à la f i n du
régime m o n o m o d e latéral).
•—i
'
1
uil |
S* 400
b
360
0)
v)
<D
-o 320
^
|
t \>
1
1
Figure 2. Images du faisceau en champ proche
résolu en longueur d'onde pour les
configurations A, B et C, pour des
puissances lumineuses semblables.
L'axe
horizontal
représente
la
longueur d'onde et l'axe vertical est la
direction latérale x.
Ces spectres d ' é m i s s i o n présentent une
i n f o r m a t i o n très c o m p l è t e . L ' a x e horizontal
représente la longueur d ' o n d e , a u g m e n t a n t
de gauche à d r o i t e .
L ' a x e vertical
représente la position latérale (direction x)
sur la face de sortie de la diode laser.
Trois groupes de modes (chaque groupe
correspondant à un m o d e longitudinal) sont
m o n t r é s dans la figure 2a; ces groupes
sont d i s t a n t s en longueur d ' o n d e de
0 . 2 n m . Dans chaque groupe, les modes
latéraux d ' o r d r e supérieur peuvent être
78
Physics in Canada
M arch/Aprill 9 9 6
ran
}
DÉPÔTS PROFILÉS
Les configurations B et C augmentent la
d i s c r i m i n a t i o n envers les modes latéraux
d ' o r d r e supérieur parce qu'elles limitent
latéralement le faisceau l u m i n e u x .
Le
m ê m e phénomène peut se produire si on
élimine la cavité externe et si le profil de
réflectivité est réalisé d i r e c t e m e n t sur la
face de sortie de la diode laser 16 '. C e t t e
approche a déjà été testée avec succès
avec d ' a u t r e s t y p e s de l a s e r s " 6 '.
Nous
avons proposé et testé dans
notre
laboratoire une technique simple pour
réaliser une couche diélectrique m i n c e
profilée sur nos diodes laser. La c o u c h e a
une épaisseur qui varie dans la d i r e c t i o n
latérale (parallèle à la jonction) et une
épaisseur c o n s t a n t e dans la d i r e c t i o n
transverse (perpendiculaire à la jonction);
elle produit donc une réflectivité profilée
dans la d i r e c t i o n latérale. Le diélectrique
utilisé est du SiO dont l'indice de réfraction
s'élève à 1.9.
Les couches minces profilées peuvent être
obtenues par deux m é t h o d e s similaires. La
première m é t h o d e consiste à placer u n
filament très mince à quelques dizaines de
microns du substrat (voir la fig. 4a).
Cloche de verre
ri
0
accord avec les simulations n u m é r i q u e s ;
les croix sur la figure 3 correspondent aux
courants de seuil calculés pour le m o d e 1.
PAO
8
240
0
20
40
60
L2 (mm)
80
100
Figure 3. Courants de seuil mesurés des modes
latéraux d'ordres 0 (cercles) et 1
(carrés) en fonction de L2 pour la
configuration
B.
Les
croix
correspondent aux courants de seuil
calculés pour le mode 1.
Les résultats suggèrent que des puissances
possibles, en régime m o n o m o d e latéral,
puissent être de plus en plus élevées à
mesure que la valeur de L 2 s'éloigne d ' u n e
plage d ' e n v i r o n 10 m m centrée à 2 3 m m .
Par exemple, pour L 2 = 1 4 m m , 2 0 m m et
60
mm,
nous
avons
mesuré
des
puissances m o n o m o d e s m a x i m a l e s de
2 1 m W , 10 m W et 4 0 m W , respectivement.
Ces résultats sont en excellent
Figure 4. Schéma du système à vide contenant
le substrat (ou la face d'émission du
laser) qui est masqué a) par un
filament de diamètre 4 ou b) par une
fente étroite de largeur w.
Le filament crée un " e f f e t d ' o m b r e " sur le
substrat,
produisant
ainsi
un
dépôt
d'épaisseur variable.
Le t e m p s de
déposition est ajusté de f a ç o n à obtenir
une épaisseur égale à X / 4 sur les bords du
substrat (X étant la longueur d ' o n d e d u
faisceau dans le SiO) et une épaisseur nulle
au centre. La pente du profil d'épaisseur
est variée en changeant la distance d entre
le filament et le s u b s t r a t . Les profils de
réflectivité les plus étroits que nous avons
obtenus (largeur totale à mi-hauteur) ont
été réalisés avec un filament de t u n g s t è n e
de 25 /Jm de d i a m è t r e placé à environ
1 2 0 / / m du s u b s t r a t .
Cependant, les
simulations numériques ont m o n t r é q u ' u n
profil aussi large n'aurait que peu d ' e f f e t
sur la d i s c r i m i n a t i o n des modes latéraux de
nos lasers.
Nous avons plutôt opté pour la seconde
m é t h o d e , qui exploite le m ê m e " e f f e t
d ' o m b r e " , mais où le filament est remplacé
par une f e n t e étroite (faite de deux lames
de rasoir). Dans ce cas, nous n ' a v o n s plus
de limite inférieure sur la largeur du profil
de réflectivité. C e p e n d a n t , le dépôt doit
être réalisé en deux étapes: d ' a b o r d une
couche profilée d'épaisseur X / 4 au centre
et zéro sur le bord, suivie d ' u n e seconde
couche d'épaisseur c o n s t a n t e (X/4) du
m ê m e matériau diélectrique. Ceci résulte
en une c o u c h e d'épaisseur X/2 au centre et
A./4 sur les bords. La figure 5 m o n t r e un
exemple de profil d'épaisseur (5a), mesuré
avec un p r o f i l o m è t r e mécanique, et le profil
de r é f l e c t i v i t é calculé correspondant
(5b).
Figure 6. Image du faisceau en champ proche
résolu en longueur d'onde émis par la
diode laser avec le dépôt profilé sur la
face de sortie. Axe horizontal: X et
axe vertical: x.
Le spectre a été enregistré à une puissance
d'environ 30 mW.
On c o n s t a t e que le
laser avec le dépôt profilé émet seulement
dans le mode latéral f o n d a m e n t a l à c e t t e
puissance.
La puissance m a x i m a l e qui
p o u v a i t être a t t e i n t e en régime d ' é m i s s i o n
m o n o m o d e latérale était inférieure à 1 m W
sans le dépôt profilé.
S I M U L A T I O N S NUMÉRIQUES
-5
0
5
position ((am)
-5
0
5
position (|im)
Figure 5. a) Profil de l'épaisseur du dépôt
obtenu avec une fente de 20 fjm
placée à 90 f j m du substrat de
verre et
b) profil de réflectivité
correspondant calculé en considérant
un substrat de GaAs.
Ce profil quasi-gaussien a été o b t e n u en
plaçant une f e n t e de 2 0 / / m de largeur à
9 0 /vm du s u b s t r a t . O n c o n s t a t e que la
largeur totale à mi-hauteur du profil de
r é f l e c t i v i t é est d ' e n v i r o n 15 / j m , ce qui
devrait être s u f f i s a m m e n t étroit pour
réduire le c o n t e n u en modes latéraux de
nos lasers. Le principal défi consistait à
centrer latéralement la f e n t e sur la fenêtre
é m e t t r i c e qui n ' e s t pas nécessairement
centrée sur la diode laser. Ce problème a
été résolu en maximisant
la
puissance
lumineuse t r a n s m i s e par la f e n t e lorsque le
laser f o n c t i o n n e sous le seuil.
Le c o u r a n t de seuil est passé de 2 2 0 m A
(sans dépôt) à 2 8 0 m A avec le dépôt
profilé. Ce c o m p o r t e m e n t était t o u t à fait
prévisible puisque la c o u c h e
profilée
d i m i n u e la r é f l e c t i v i t é globale de la face de
sortie.
T o u t e f o i s , l ' e f f i c a c i t é quantique
différentielle a été légèrement améliorée,
passant de 0 . 5 4 W / A à 0 . 6 4 W / A .
La figure 6 m o n t r e l ' i m a g e du faisceau en
c h a m p proche résolu en longueur d ' o n d e
obtenue avec la diode laser ayant un dépôt
profilé sur la face de sortie.
Les logiciels de s i m u l a t i o n que nous avons
développés ont été utilisés pour le calcul
des caractéristiques d ' é m i s s i o n des diodes
laser
opérées
dans
les
diverses
configurations
présentées
dans
les
paragraphes précédents. Ces p r o g r a m m e s
utilisent la m é t h o d e de propagation de
faisceaux' 1 0 ' pour simuler la propagation
du
c h a m p optique dans le laser, un algorithme
de t r a n s f o r m a t i o n d ' é c h e l l e " " pour la
p r o p a g a t i o n dans la cavité externe (s'il y a
lieu) et l ' a l g o r i t h m e de Prony" 2 1 pour
extraire les d i f f é r e n t s modes latéraux (et
leur valeur propre associée) pour t o u t e s
les c o n f i g u r a t i o n s . Les logiciels tiennent
c o m p t e des variations latérales du gain, de
l ' a b s o r p t i o n , des e f f e t s t h e r m i q u e s , des
variations latérales de l'indice de réfraction
induites par la d i s t r i b u t i o n des porteurs de
charge
et
de
la
déplétion
de
la
c o n c e n t r a t i o n des porteurs par le c h a m p
optique due à l ' é m i s s i o n stimulée. Nous
nous s o m m e s intéressés aux e f f e t s de
l ' u t i l i s a t i o n de c a v i t é s externes et de
dépôts
profilés sur la
discrimination
modale, les caractéristiques du mode
latéral f o n d a m e n t a l intracavité et celles du
faisceau t r a n s m i s dans l'air en c h a m p
proche et en c h a m p lointain. Nous avons
aussi calculé les caractéristiques telles le
courant de seuil requis pour atteindre le
régime d ' é m i s s i o n stimulée et l ' e f f i c a c i t é
q u a n t i q u e différentielle.
Les valeurs des paramètres optiques,
électriques et t h e r m i q u e s utilisées dans les
simulations numériques ont été ajustées à
celles des lasers EG&G de
modèle
C 8 6 0 9 0 E ; celles-ci peuvent être retrouvées
dans les tableaux I et II de la référence 1 3.
Nous avons calculé une très faible
d i s c r i m i n a t i o n envers les modes latéraux
d ' o r d r e supérieur pour la diode laser sans
dépôt sur la face de sortie et sans miroir
externe.
En e f f e t , le rapport |yo j /1Y1 [
entre les valeurs propres des deux modes
qui ont les plus faibles pertes vaut 1 . 0 1 6 ,
dans ce cas. Ceci est cohérent avec nos
résultats e x p é r i m e n t a u x qui m o n t r e n t que
la puissance m a x i m a l e pour laquelle le laser
sans dépôt émet sur un seul mode latéral
est inférieure au m i l l i w a t t .
Pour la c o n f i g u r a t i o n B, la d i s c r i m i n a t i o n
jyo | /1Y1 I a été calculée pour d i f f é r e n t e s
valeurs de L 2 . Cette étude a révélé que la
discrimination
reste inférieure à
1.1
seulement pour les valeurs de L 2 c o m p r i s e s
entre 15 et 2 9 m m . Dans cet intervalle, le
faisceau qui revient dans la diode laser
après son trajet dans la c a v i t é externe est
tellement étroit q u ' i l ne subit pas de
filtrage spatial dû à la largeur finie du
milieu de gain. À mesure q u ' o n s'éloigne
de cet intervalle, le faisceau de retour
s'élargit et la d i s c r i m i n a t i o n a u g m e n t e . La
figure 2b a été obtenue avec une valeur de
L2
égale à 1 0 0 m m et une bonne
discrimination
a
effectivement
été
observée.
D ' a u t r e part, les croix de la
figure 3 m o n t r e le courant de seuil calculé
pour le m o d e latéral d ' o r d r e 1 en f o n c t i o n
de la longueur L 2
pour la diode laser
opérée dans la c o n f i g u r a t i o n B. Ces points
m o n t r e n t un bon accord avec les résultats
e x p é r i m e n t a u x obtenus.
Pour la diode laser avec un dépôt profilé
(sans cavité externe), nous avons supposé
que la réflectivité de la face de sortie était
décrite par la f o n c t i o n 0 . 3 e x p ( - x 2 / w m 2 ) ,
où x est la d i r e c t i o n latérale et w m la
demi-largeur à 1/e du m a x i m u m .
La
figure 7 m o n t r e la d i s c r i m i n a t i o n | Y o | / | y 1 |
en f o n c t i o n de la largeur du profil de
réflectivité, telle que calculée au seuil de
l ' é m i s s i o n laser.
Figure 7. Discrimination |yo|/|y11 en fonction
de la largeur w m du profil de
réflectivité.
L'amélioration
de
la
discrimination
s ' a c c o m p a g n e d ' u n e légère hausse du
courant de seuil. L ' é v o l u t i o n du courant de
seuil en f o n c t i o n de w m est m o n t r é e
à la figure 8. Par e x e m p l e , avec 2 w m =
1 5 / / m (largeur du dépôt profilé sur la diode
laser de la section précédente), le courant
de seuil est 1.25 fois plus élevé que sans
dépôt (passant de 2 2 6 à 2 8 0 m A ) , ce qui
correspond
très
bien
aux
résultats
e x p é r i m e n t a u x o b t e n u s (le seuil passant
alors de 2 2 0 à 2 8 0 m A ) .
400
Figure 8. Courant de seuil de l'émission laser en
fonction de la largeur du profil de
réflectivité pour une réflectivité
centrale de O.3.
PERSPECTIVES
Les techniques décrites dans cet article
o f f r e n t plusieurs degrés de liberté pour le
79
c o n t r ô l e des m o d e s latéraux dans les lasers
à s e m i - c o n d u c t e u r s à guidage par le gain et
elles
requièrent
un
équipement
généralement accessible dans t o u s les
laboratoires d ' o p t i q u e .
Les m é t h o d e s
d é c r i t e s pour réduire l ' o s c i l l a t i o n des
modes latéraux d ' o r d r e supérieur peuvent
être appliquées à des lasers à large ruban
encore plus puissants que ceux dont nous
disposions.
Les simulations numériques
e f f e c t u é e s se sont avérées en bon accord
avec les résultats e x p é r i m e n t a u x .
À m o y e n t e r m e , nous p r é v o y o n s utiliser un
réseau à r é f l e c t i v i t é profilée en c a v i t é
e x t e r n e p o u r r e s t r e i n d r e le s p e c t r e
d ' é m i s s i o n à un seul m o d e longitudinal et
latéral et à en accorder la fréquence. Nous
avons mis au point u n procédé de
f a b r i c a t i o n de tels réseaux par interférence
de faisceaux gaussiens sur une photorésine.
Une telle source serait une alternative
c o m p a c t e et peu c o û t e u s e aux lasers
présentement utilisés en spectroscopie.
11.
A . E. Siegman, Lasers , Mill V a l l e y :
University
Science
Books,
pp.
805-811 (1986).
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A . E. Siegman and H. Y. Miller, A p p l .
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C. Chang-Hasnain, J . Berger, D. R.
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J . A . R u f f , A . E. Siegman, and
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W . F. Sharfin, J. Seppala, A . Mooradian,
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S.
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ozone, and hydrogen peroxide, A t m o s .
Env. 2 8 , 1 7 8 1 - 1 7 9 0 , 1 9 9 4 .
Benkovitz, C . M . ,
C.M.
Berkowitz,
R.C. Easter, S. Nemesure, R. Wagener,
S.E. Schwartz, Sulfate over the North
Atlanticand adjacent continental regions:
Evaluation for October and November
1986 using a three-dimensional model
d r i v e n by
observation-based
meteorology.
J . Geophys. Res. 9 9 ,
2 0 7 2 5 - 2 0 7 5 6 , 1994.
4.
Bridgeman H . A . , J . L . W a l m s l e y and
R.S. Schemenauer, Modelling the
spatial variations of w i n d speed and
d i r e c t i o n o n Roundtop
Mountain,
Quebec.
Atmosphere-Ocean
32,
605-619, 1994.
5.
Byun D . W . and R. Dennis, Design
a r t i f a c t s in Eulerian air quality models:
e v a l u a t i o n of the e f f e c t s of layer
thickness
and
vertical
profile
correction
on
surface
ozone
concentrations, Atmos.
Env.
29,
105-126, 1995.
6.
Flueck J . A . ,
measures of
T e n t h Conf.
Statistics in
M e t e o r . Soc.,
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H o f f R . M . , R.E. M i c k l e and C. Fung,
V e r t i c a l profiles of ozone during the
EMEFS I Experiment in S o u t h e r n
Ontario, A t m o s . Env. 2 9 , 1 7 3 5 - 1 7 4 7 ,
1995.
8.
Karamchandani P. and A . V e n k a t r a m ,
The role of non-precipitating clouds in
producing ambient sulfate during
summer:
results f r o m simulations
w i t h the acid d e p o s i t i o n and oxidant
model ( A D O M ) . A t m o s . Env. 2 6 A ,
1041-1052, 1992.
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REFERENCES
REFERENCES
1.
10.
Y . Champagne, S. Mailhot and
N. M c C a r t h y , IEEE J . Q u a n t u m
Electron. 3 1 , 7 9 5 ( 1 9 9 5 ) .
Evaluation of the Acid . . . by C. M. Banic
et al. (continued from pg. 76)
REMERCIEMENTS
Nous r e m e r c i o n s M . Marc D ' A u t e u i l pour
son support technique et ses judicieux
conseils et M . David Gay pour l'aide
apportée à la préparation des figures. Ces
travaux n'auraien t pu être réalisés sans
le s o u t i e n financier d u CRSNG et du
FCAR. Si v o u s désirez plus d ' i n f o r m a t i o n s ,
nous v o u s i n v i t o n s à c o m m u n i q u e r avec
nous
à
l'adresse
électronique
nmccar@phy.ulaval.ca.
ozone c o n c e n t r a t i o n s at a select set
of high-elevation sites in the Eastern
United States, Environ. Pollut. 6 7 ,
147-178, 1990.
Macdonald
A.M.,
C.M.
Banic,
W.R.
Leaitch,
K.J.
Puckett,
Evaluation of
the Eulerian
Acid
Deposition
and
Oxidant
Model
( A D O M ) w i t h s u m m e r 1 9 8 8 aircraft
data. A t m o s . Env. 2 7 A , 1 0 1 9 - 1 0 3 4 ,
1993.
Schemenauer R.S. and K.G. A n l a u f ,
Geographic
variation
of
ozone
concentrations at high and
low
elevation rural sites in Quebec. N o r t h
American
Oxidant
Symposium,
Quebec C i t y , Canada, 2 5 - 2 7 Feb.,
412-429, 1987.
12.
Schemenauer R.S., C . M . Banic and
N. Urquizo, High elevation fog and
precipitation c h e m i s t r y in S o u t h e r n
Quebec, Canada. A t m o s . Env. 2 9 ,
2235-2252, 1995.
13.
V e n k a t r a m A . , P.K. Karamchandani
and
P.K.
Misra,
Testing
a
c o m p r e h e n s i v e acid d e p o s i t i o n model.
A t m o s . Env. 2 2 , 7 3 7 - 7 4 7 , 1 9 8 8 .
The Editorial Board
welcomes articles
from readers
suitable for, and
understandable to,
any practising or
student physicist.
Review papers and
contributions of
general interest are
particularly
welcome.
A s t u d y of some
forecast v e r i f i c a t i o n .
on Probability
and
A t m o s . Sci., A m e r .
Boston M A . , 6 9 - 7 3 ,
Le mouvement pour la santé active
S Y M M E T R Y - V I O L A T I N G NN POTENTIALS IN T H E N U C L E U S
by
A . C . Hayes, A E C L , Chalk River Laboratories, Chalk River, Ontario, Canada KOJ 1J0
ABSTRACT
The parity-violating and time reversal noninvariant nucleon-nucleon interactions are reviewed, and their manifestation in the nucleus discussed.
INTRODUCTION
Major advances in our understanding of the weak
interaction have come from low energy nuclear
studies. The best examples come from nuclear (idecay measurements which established the existence
of the neutrino and the fact that the interaction does
not conserve parity. The very high precision jS-decay
measurements that are possible today provide stringent
tests of the weak currents in the Standard Model. Test
of the weak interaction from semi-leptonic processes
have been reviewed recently by Towner and Hardy
[ 1 ] . In this article I will concentrate on another aspect
of the weak interaction, namely, the non-leptonic paît.
In particular, I will discuss the weak parity-violating
and time-reversal-violating nucleon-nucleon
interactions, and studies of these in low-energy
nuclear experiments.
The weak interaction is responsible for pure leptonic
processes such as ^-decay <jr — tr + vt + v/i),
semi-leptonic processes such as j3-decay (e.g., n — p
+ e~ + vr), and non-leptonic processes such as A 0
— p + t~ decay. The three classes of the weak
interactions can be split further into two parts
depending on whether strangeness is conserved or not.
In the case of the non-leptonic weak interaction
information on the strangeness changing
(AS = ± 1) part of the Hamiltonian is obtained by
studying the weak decays of elementary particles, for
example, the decays A — M r , K — 2 x , 3 t , £
— M r . However, for the strangeness conserving part
of the Hamiltonian, the allowed strong interaction
processes will generally render unobservable any
expected manifestation of the weak interaction. Thus,
it is not feasible to study the AS = 0 non-leptonic
part of the weak interactions using elementary particle
processes. However, the weak Hamiltonian gives rise
to a weak nucleon-nucleon potential and part of this
potential does not conserve parity. Manifestations of
the parity nonconserving (PNC) weak N N potential
are seen in the low energy nuclear physics processes.
These processes, though difficult to measure and to
calculate, provide the only source of information on
the AS = 0 non-leptonic weak interaction.
The goal of studies of parity non-conservation in the
nucleus is to determine the strength of the coupling
consttants for the weak N N interaction, and to
determine the interplay between the strong and weak
interactions in the nuclear many-body system.
Extracting information on the coupling constants for
the parity violating N N potential from such
measurements requires knowledge of both the weak
interaction and of the effects of nuclear structure on
its manifestation in these rare nuclear processes. The
nonleptonic weak irteraction is an interaction between
the quarks and is mediated by the W and Z bosons.
However, in the low-energy regime of the nucleous
it is more efficient to describe the weak interaction
in terms of an effective potential between nucléons
mediated by mesons. The physics of the weak
nucleon-meson amplitudes (N M | 3C. | N) then
appears as an effective weak N — NM coupling
constant. These effective coupling constants are
calculated within quark models for the nucléons and
mesons starting with the fundamental weak interaction
between quarks. Reliable values of the effective
The full expressions for the weak and strong verte\
Lagrangians and for the resulting six PNC potertials
for r(AT = 1). p(AT = 0, 1, 2), and u>(AT = 0, 11
exchange are given in refs. [4,6]. Both quark model
analyses [ 4 ] for the weak matrix elements ( N M
3C„ j N) and theoretical nuclear structure analyses
[ 6 ] of experimental data indicate that of the
corresponding six coupling constants, FT, F0, F\, F:.
and G0 and G,, only the isoscalar F0, coefficient 01
the p-potential and the isovector FR, coefficient of
the x-meson potential contribute importantly. The
expressions for these two PNC potentials are:
N
N
n, p, to
&
-
-
-
-
-
-
-
0
2
F _
M'
_ | T «vc = ,_ï
(r|Xr2)!(Ol+02)
N
F
M2
M
2i
r y.co
Kit*,)
N
Fig. 1. The ooe-meson-exchange contribution to the weak
parity-violating NN interaction. Here one nucléon emits
a meson via the weak irteraction (depicted by the crossedcircle vertex and a second nucléon absorbs the meson via
the strong interaction (depected by the open-circle vertex).
coupling constants for the weak NN potential would
provide very useful tools for verifying the quark
model caclulations.
THE PARITY V I O L A T I N G N N P O T E N T I A L
The strong N N potential is well described in terms
of the exchange of mesons ( r , p , u , ...) between the
nucleous. A natural extension of these models for the
weak N N potential is a meson exchange model in
which one nucléon emits a mesons through the weak
interaction and a second nucléon absorbs the meson
via the strong irteraction (Fig. 1). The studies of
parity violaiton in the nucleus are carried out in the
low-energy regime. This, taken with the fact that the
NN potential is strongly repulsive at short distances,
means that only the lightest mesons are important for
the PNC potential. Thus, we might expect the onepion exchange diagrams to dominate. However, it
turns out that CP invariance severely restricts the onepion exchange cortri>utions to the PNC potential. The
limitation arising from CP invariance, which applies
equally to any neutral pseudoscalar (e.g., T", 770,
etc.) meson, is called Barton's Theorem. Barton [2]
and later Henley [ 3 ] showed that for these mesons
the P-violating meson-nucléon vertex function is not
invariant under CP and must vanish for CP-invariant
weak interactions. For the charged pions ( x * ) a CP
invariant coupling can be constructed, but k is
restricted to an isovector (AT = 1) interaction. For
this reason contributions to the weak PNC potential
arising from the exchange of vector mesons,
particularly isoscalar (AT = 0) p-exchange, are
important. Significant contributions to the PNC
potential are then expected from r,p, and <i>-exdiange.
where mr (mp ) is the pion (rho) mass, A/the nucléon
mass, and ii v is the nucléon vector magnetic moment.
I i v = 3.7. Here the z-symbol on the isospin vector r,
x t 2 indicates the third component of the vector.
Also, r = r1 —r2, xT = mTr and y,(jr) = (1 +
Vx)Y0(x) with Y0(x) = e ~"/x. The coupling constants
FT and F0 involve the product of one weak and one
strong vertex coupling constant and their strengths
remains a central issue in PNC studies.
Hie different isospin structure of the two potentials
means that differert linear combinations of F0 and
FT are involved in PNC effects in different nuclei.
For example, a parity mixing between two states thai
differ by one unit of isospin is determined solely H>
FR, while a mixing between two stales that differ h\
a proton (neutron) excitation involve a constructive
(destructive) linear combination of F0 and F r . Thus
in principle, measurements of PNC effects in three
or so rnclei could determine reliable values for the
weak coupling constants.
Evaluating matrix elements of the PNC potentials
between two-nucleon states requires a transformation
of the wave functions from a single particle coordinate
system to a relative and centre of mass coordinate
system. The required coefficients (Moshinsky
brackets [ 5 ] ) for this transformation are known for
harmonic oscillator wavefunctions. However, the
eigenfunctions of the harmonic oscillator potential are
not the eigenfunctions of the nucleon-nucleon
irteraction. The most serious shortcoming of the
harmonic oscillator wave functions is their inabilk)
to describe the short-range repulsion of the NN
irteraction. This strong repulsion means that as
r — 0 the relative wave functions go more rapidly
to zero than given by uncorrelated oscillator functions
However, the physics of the short-range repulsion can
be incorporated phenomenologically by mu k iply in^
the two-body potentials by a short-range correlation
function. Thus we write
ïpNdr)
The expressions for the weak PNC potentials are
obtained by combining one strong and one weak NMvertex Lagrangian with the meson progator, and
taking the non-relativistic limit of the vertex functions.
(D
=
VmdrWr).
(2)
where §(r) is some function that tends to zero as
r — 0 and tends to unky for large r. The standard
choice is that made by Adelberger and Haxton [6]
81
who used g(r) = [ 1 - expi-ar2)^ 1 - br2)]2 with
a = l.lfin'2 and b = 0.6SJm'2 obtained from the
work of Miller and Spencer [ 7 ] . Typically, the short
range correlations reduce the r-exchange matrix
elements by a factor of - 1 . 4 and the p-exchange by
- 3.6 [ 6 ] ,
DETECTION OF PARITY VIOLATION IN THE
NUCLEUS
mukipolarity (and necessarily of opposite parity) are
emitted. A parity-violating asymmetty can be detected
by searching for circularly polarized photons resulting
from the interference between the two types of
radiation. Alternatively, if the ruclear level has been
polarized, a search can be made for an asymmetry
of the emitted photon relative to the direction of
polarization.
Several such experiments have been performed [ 8 ] .
These are three very favourable cases were both
sources of amplification of the PNC signal play a role.
These occur in 18F, 1SF and 21Ne where parity
doublets are found in the low-lying bound states of
the nucleus. Most of the theoretical work has
concentrated on these three doublets and detailed
analyses have been carried out within the shell model
E + -£_
framework. [ 6 ] . Inthecase of "Fthere is a0~, 0 +
= <t>J+ + S
<
t
>
j
(
3
)
doublet lying at 1081 keV and 1042 keV, respectively.
All searches for circular polarization in the 7-decay
The matrix elements (<t>j_ \ Vmc \ <j>J+ > are - 1 eV. of the 0 " 1081 MeV state yield a zero result, and
In a light spherical nucleus a typical nuclear splitting
theoretical analyses of this result indicate an upper
between states of the same J but opposite parity is
bound on the value of F t that is consistent with zero.
E+ —E_ ~ 1 MeV, so that the odd parity amplitude
While this bound is allowed by quark model
is î — 10 . However, in complex nuclei one finds
calculations of the effective weak coupling constants,
situations where the energy splitting between states
itrequiresconsiderable cancellation amongst different
+
] and J~ are considerably smaller that 1 MeV, and
model contributions. Tlie unexpectedly small value
in these cases there is an amplification of the PNC
of FT has in part motivated the morerecentsearches
signal. Indeed, many of the PNC searches focus on
for parity-violating effects in different nuclear mass
+
parity-doublets, i.e., closely spaced J , J~ pairs.
regions.
Exploiting this enhancement can have its
disadvailages when it comes to interpreting the
The largest parity-violating effects have been seen in
measurements. This is because very precise
measurements of the (helicity dependent) longitudinal
knowledge of the nuclear wave functions is needed
analyzing powers for polarized neutron scattering. In
to extract information on the weak interaction —
neutron transmission experimerts on heavy nuclei,
considerably more precise than is needed in most
the parity-violating asymmetries, which are defined
analyses of parity-conserving observables. Hie largest
as the fractional difference of the resonance cross
PNC signals are seen in heavy nuclei where nuclear
section for neutrons polarized parallel and antiparallel
levels are very closed spaced, but the nuclear structure
to their momentum,
problems become enormously harder as the
complexity of the nucleus increases. For this reason,
a+ -a~
P =
(4)
the approach to analyses in light versus heavy nuclei
a
+0
have followed very different paths.
can be as large as 10% [ 10]. These measurements
are made on p-waveresonancesin compound ruclear
Parity inversion refers to the spatial transformation
systems such as 2 M U and 232Th [11]. In these
r — —r, which implies a momentum transformation
systems the energy separation between opposite parity
k — -k. The angular momertum vector (L = r x
j-wave and p-waveresonancesrange from 0.1-100
k) and the spin vector (a) are unchanged under parity.
eV. The mixing of one s- wave state in a p-wave state
Thus, measuremerts usually involve searches for
leads to a longitudinal asymmetry
parity-odd observables such as (a.k), which can arise
The parity-violating potential is a very small part
(10 — 10 - 6 ) of the total Hamikonian for a nuclear
system, H = Hq + V ^ Thus, it can be treated in
perturbation theory, and the eigenfo net ions of H can
be written
from an interference between a parity-conserving and
a parity-violating amplitude. These parity-odd
correlations are first order in 3\ Alternatively, one
can search for violation of parity-forbidden selection
rules, such as a parity-forbidden a-decay, and these
are proportional to & 2 .
In the case of parity-odd observables arising from an
irterference between a parity-conserving and paritynonconserving amplitude a second enhancement of
the signal is possible. The PNC effect is proportional
to
(CHPNC)>
25 —
- , where <CHPNC)> is the matrix
(i0{PQ>
element of an observable which is now non-zero
because oftheP-violation and <0(PQ> is the matrix
element of the parity-conserving observable. Thus,
by choosing cases where nuclear structure effects
render <0{PQ> to be very hindered, the PNC signal
can be amplified significantly.
Most of our knowledge on the PNC potentials have
come from measurements of parity-violating
asymmetries seen in y-decay, or in the scattering of
polarized nucléons from nuclei. In the case of the
photon decay of an excited parity-mixed state of the
mcleus (eq. (3)) to a final state of definite parity, both
magnetic and electric radiation of the same
82
Physics in Canada M arch/Aprill 9 9 6
p = 2 * 4
(5)
yp
Here 7" and 7J are the neutron reduced-widths
evaluated at the p-wave resonance energy. The actual
asymmetries involve a summation over many i-wave
resonances since it is unlikely that P is dominated by
the nearest-neighbour opposite-parityresonance.The
large size of the PNC asymmetries in compound
systems arises because of (1) the small energy
denominators in 7 and (2) the favourable ratio of
j-wave to p-wave neutron widths.
The close spacing between theresonancesreflects
their complexity and they correspond to highly excited
compound states of the nucleus. The wave fonctions
of theseresonancesinvolve 105-106 single particle
componerts, and their structure can only be described
statistically. In the statistical model the neutron
reduced widths 7" and
and the PNC mixing
matrix elements < VFNC) are treated as independent
Gaussian-distributed random variables with zero
mean. Using the known values of the resonance
energies and reduced widths, the root-mean-squared
PNC mixing matrix element M can be determined
directly from a set of experimental values of P. A
maximum likelihood analysis [11] yields a value
^>2]
M=lAv<ipIK^I
w
= 0 . 5 8 ^ « t K (6)
where <ps and \pp are the s- and p-wave resonance
wave functions.
The observed magnitude of M is about as expected
since the density of stales in compound systems is
about a thousand times larger than in light nuclei and
the average PNC matrix element there is - 1 eV.
French et al. [12] have developed a microscopic
framework for a statistical treatment of ruclear
properties. The formalism has been applied
successfully to studies of strength functions of positive
parity operators, such as the quadrupole operator, in
compound nuclei. Tomsovic [ 13] has proposed an
extension of the theory for studies of PNC matrix
element s. The first step in this direction has been taken
by Johnson et al. [14] who examined the PNC
strength function in large shell model spaces and
compared this to the measured value of A/to extras
a range of values for Fx and F0.
An example of a violation of a parity-fortiidden
selection rule is the a-decay of the excited 2 "(8.87
MeV) state of 16 0 to the 0 + ground state of U C;
16
0(2
— aC + a . The a-particle has spin/parity
J = 0 + , and it can carty away L units of angular
momertum. Thus, in the absence of parity violation,
only states in 12C with J = 2 +L and parity II =
( - ) 1 + i can be populated by the decay of a2~" state
A parity-violating o-width of r a = (1.03±0.28) X
10" 10 eV has been measured [ 15] for this stale.
This width arises from a 2 + amplitude 7 admixed
into the 2 ~ state, and the magnitude of the PNC
width is proportional to Or2. Unfortunately, the
uncertainties in the calculation [ 16 ] of this admixture
have proved too large to extract information on the
weak potential from this mea su renier».
THE ONE-BODY PNC POTENTIAL
The PNC potentials are two-body potentials, and the
largest uncertainties in evaluating their matrix
elements between many-body ruclear states arise from
the uncertainties in nuclear wave functions
themselves. Diserlanglingthe nuclear structure from
the underlying weak PNC matrix elements is the moa
challenging aspect of any theoretical analysis ol
nuclear parity violation. Insight into the complexities
involved and into any pertinent shortcomings with the
model wavefonctionscan be obtained by starting with
an analysis of the problem within a one-bod)
approximation. Michel [17] derived an effective onebody PNC potential, which allowed him to evaluate
PNC asymmetries using Nilsson model wave
functions for a variety of spherical and deformed
nuclei.
Typical many-body nuclear calculations assume an
inert core set of nucléons (interacting only via the
average nuclear potential) and a valence set ol
interacting nucléons. The one-body PNC interaction
Ume between two nucléons in valence states | a)
and I b) can be derived from matrix elements of the
two-body interaction V w c by summing over all
configurations in the core,
(b I UpncI a> =L<b,c I » W 0 . 2 ) I a, c> (7)
c
Here the two-body matrix element is antisymmetric,
i.e., it includes both the direct and exchange terms.
The matrix elements of the one-body inet eract ion can
be expressed in terms of an analytic one-body
operator. The chosen operator acts as a meaningful,
well-defined approximation to the two-body PNC
potential if the associated effective coupling constants
are not dependent on the core states involved in the
sum (7). The simplest and most appealing one-body
operators that violate parity, but not time-reversal
invariance, are the isoscalar and isovector axial
operators 7- p and 7-pr. The appropriate effective
coupling constants are defined as
a)
<b I
T A B L E I. C o n t r i b u t i o n f r o m each c o m p o n e n t ( F » , F o , . . . G i ) of the two-body VPNC to e for
closed-shell-plus-one configurations for five choices of t h e closed-shell core.
7-pr
(>
Most striking is the lack of any strong shell or mass
dependence in the coupling constants t° or e 1 . The
total isoscalar and isovector PNC strengths remain
almost constant with A (the mass of the nucleus).
Furthermore, the large neutron excess in heavy nuclei
has little effect on the values of the effective coupling
constants. There are two competing factors
determining the mass dependence of e. First there is
the dependence on the size of the nucleus, which
increases linearly with the harmonic oscillator length
parameter, bocA 1/6 . Matrix elements of 7-p scale
with 1/b, while matrix elements of VPNC scale
roughly with 1/b 2 . Thus, if the number of core
orbitals which are summed remained fixed, t would
scale like 1/b approximately, and thus decrease
roughly as A - . However, this scaling with the
oscillator parameter is strongly offset by the increase
in the number orbitals being summed as A increases.
In general, the two effects compensate, resulting in
an approximately mass independent effective coupling
constant.
f°
Fo
Fi
F2
Go
G,
Total
t{9
r)
eV
-.205
-.126
- 136
-.157
-.150
2.7
2.5
r
u«
itijiklli
CT.P
1
IL
1
i u
1
1]
ml l H
10
26
E'(MeV)
To examine the expected distribution of the PNC
strength in the nucleus we can examine the strength
functions of the effective one-body operators. "Hie
axial operators 7- ?and 7- pr are exactly analogous
to the electric spin dipole operators 7• 7and 7• ir.
They differ in their helicity properties, but if we
confine ourselves to a 0l)o) — 11)0) calculation, (i.e.,
a calculation where the positive and negative parity
stales differ only by the excitation of a nucléon
through one oscillator shell), the distribution of the
matrix elements of 7-"and 7- p are identical. The
operators a,r, and a • r generate the group SU(4), and
the irreducible representations of this group form the
Wigner Supermultiplets. If the nuclear force were
independent of spin and isospin, i.e. invariant under
the Wigner SU(4) symmetry, the distribution of
matrix elements of any set of operators 0(r), 0{r)a,
0(r)R, and CHDOT would be the same. The nuclear
Hamikonian does contain SU(4) noninvariant terms,
such as the Heisenberg ( j y r 2 ) interaction and the
spin-orbit interaction. Nonetheless, the distribution
of operators differing only by an SU(4) rotation
remains similar, particularly in light nuclei. The
operator TV is the electric dipole operator and ks
strength distribution in the nucleus is determined by
the giant dipole resonance which lies at about 1.5I)o),
(t)oj =
MeV) of excitation, and is a few
MeV wide. Thus, from SU(4) symmetry arguments,
we expect that the strength distributions for 7-p and
7• pr also exhibk resonance-like structure.
To demonstrate this in a realistic calculation we
consider the nucleus 19 F which has a 1/2 + ground
state. The parity mixing between the ground state and
the first excited 1/2 ~ state has been deduced from
Fig. 2 The distribution or one-body PNC strength built
on the J = 1/2 * ground state or F. In this Figure the
height of each line represents the magnitude or the PNC
matrix element (in arbitrary units) and the energy
position or the line is the excitatioa energy or the
corresponding T = l/2 or T - 3 / 2 7 = 1 / 2 " excited state.
The PNC matrix elements were obtained from a lffui shell
model calculation. The upper panel oT the figure shows
the one-body strength derived from the two-body PNC
interaction using eq (7). The lower panel shows the
strength obtained using the operators e° 7 • p and
e ' 7 • pr, where the coupling constants e* and e ' are taken
to be orbital independent. We note the very snail fraction
oT the total strength to the fin* 1/2 "(100 keV) state. This
is the state that is relevant to the parity-violating 7-decay
in "F.
the y decay of the 1/2" state. The total (isoscalar
and isovector) one-body PNC strength built on the
ground slate of 19 F is shown in detail in Fig. 2. The
states of 19 F were calculated in a full (0+ l)f)o) shell
model calculation, in which spurious centre-of-mass
exckations were removed exactly. There are then over
three hundred 1/2 ~ states in the nonspurious model
space. From Fig. 2 k can be seen that most of the
strength of the parity-violating interaction is
concentrated at higfi energies, and that the first excited
state involves only a very small fraction of the total
strength. This points to the need for a very detailed
calculation of the structure of this state before a
meaningful analysis of the PNC matrix element can
be extracted from the 7-decay measurements. The
upper panel of the figure shows the PNC strength
obtained using the full form of the PNC potential via
eq. (7), the bottom panel shows the results obtained
- 135
2.3
132
- 144
- 001
.005
-.008
-.166
2.5
3 0
-.119
- 015
-.014
-.008
-.213
r1]
3p-3s
-.140
-.001
000
-.014
-.007
1 I,
3p-3s
- 157
-.001
.000
-.014
000
2p-2s
337-Th
N=142
Z=90
e1
- 143
-001
.000
2 4
™Pb
N=126
Z=82
lp-ls
- 156
-170
I
Zr
N=50
Z=40
<>
Op-Os
II a)
The contribution of each of the six terms in VFNC
to the one-body coupling constants
and e 1 has
been calculated by Hayes and Towner [18] assuming
a single nucléon outside a closed-shell configuration.
The results are summarized in Table 1.
I
Ca
N=20
Z=20
e°
(8)
F.
OH
I
160
N=8
Z=8
001
.005
-.016
009
-.009
-.155
2.6
-129
2.2
-
160
2.7
128
2.1
using the operators 7-p and «• Jr. The two
distributions are very similar over the entire excialion
spectrum. However, for some individual states large
differences occur. This suggests that whilst the
operator 7 • ? provides an excellent approximation to
the overall PNC strength function in the nucleus, it
should not be used for the extraction of PNC coupling
constants from measurements on isolated parity
doublets.
T-VIOLATTON IN THE NN INTERACTION
Since the discovery of CP-violation in kaon decay
over thirty years ago, the origin of the effect has still
not been identified. There have been many searches
for other CP-and T-violating effects, but nothing has
been seen in systems other than the neutral kaons.
A number of models have been proposed for the
interaction responsible for the observed CP-violation.
The observed effect can be accounted for wflhin the
minima] standard model through a CP-violating phase
in the Cabibbo-Kobayashi-Maskawa quark mixing
matrix. Akernatively, new interactions requiring an
extension of the standard elect roweak model may be
responsible, and the predictions of some of the
proposed models are quke different in systems other
than the neutral kaons. T-violation in the NN
interaction can occur simukaneously with P-v»lation,
or as a P-conserving T-violating, interaction.
However, in contrast to the PT-violating interactions,
interactions that violate T but conserve P do not arise
in the standard model. In this section we discuss
attempts via low-energy measuremerts to put limits
on the strengths of either form of T-violation in the
NN interaction.
The time-reversal noninvariart low-energy NN
potentials can be described in terms of a single meson
exchange in which one of the N — NM vertices
involves a P,T-violating or T-violating P-conserving
non-leptonic Hamikonian. Measurements of Tviolation in the nucleus require polarized nuclear
targets, and are generally more difficuk than searches
for P-violating T-conserving asymmetries. The
magnitude of a T-violaling amplitude in the nuclear
wave functions is expected to be vety small, especially
in the case of a T-violating P-conserving amplkude.
The issues involved in the PT-violating and the Tviolating P-conserving interactions are differert and
we consider them separately. The most stringeit tests
on the limits of time-reversal noninvariant interactions
come from searches for electric dipole moments in
the neutron or in neutral atoms. However,
investigations of the role of T-violation in the NN
interaction have concentrated on searches in the
nucleus. We first consider the simukaneous violation
La Physique au C a n a d a
m a r s à avril 1 9 9 6
83
of time reversal invariance and parity conservation.
P,T-violalion in the NN interaction may be studied
in 7-decay and in neutron transmission on polarized
nuclei. PT-violalion is always accompanied by Pviolation alone, and the ratio of the two asymmetries
is the relevant observable. A symmetry-violating
potential VF + VF,T has the effect of changing a
nuclear stale | a ) to a state |/4>, given by
a
M > - |fl>+E. l ' >
((o' \VF\a)
+
(a'\VF,T\a))
(9)
situation seen in P-violation, where p-exchange plays
a dominant role.
As noted above, the ratio of the P,T-violaling to Pviolaling asymmetries is the significant observable and
this is proportional to the ralio of the malrix elements
of VF and VFJ. Herczeg [ 19] has poitled out that
if a reliable calculation of (a'|VF,T | a) is not
available, an estimate of the ratio ArT!AF combined
with a measured value of the P-violaling effect may
give a more reliable estimate of (a 1 Vr,T\a ) than
would an unreliable calculation of it. To this end,
Herczeg defines the ratio k.
where the state | a ' ) is of the same angular
momentum as \a) but of opposite parity.
We recall that for P-violation alone, CP-invariance
excluded T = 0 and T - 2 t-exchange. For Ihe P.Tviolating potentials this restriction no longer holds,
and T = 0 , 1 and 2 x-exchange are allowed. The
isotensor potential is not generally expected to play
a dominant role. The expressions for the T = 0 and
1 x-exchange P,T-violaling potentials are [19,20]
2
(10)
where a + = a t + a 2 ,
for r + and r_.
— <rl — o^ and similarly
In the case of P-violalion alone, p-exchange is known
to be as important as x-exchange. The T = 0 and 1
p-exchange P,T-violaling potentials are [21]
• W
- PSutim
-o.-ÏTDY&J
^ « -
f ' l l W
(ID
The coupling constants g $ w characterize the P,Tviolating// — NM vertices and the coupling constarts
Smnn ( l >e ^rong vertices. (We are following the
standard notation in which a 'bar' over the coupling
constant indicates T-violation and a 'prime' Pviolation. A "bar' and a 'prime' together indicates PTviolation). The overall form of the p-exchange P,Tviolating potentials is the same as for x-exchange
except for one key difference in the isovector
potential. There the relative sign between the two
terms is negative for p-exchange and positive for
x-exchange.
To obtain insight into the properties of the P,Tpotentials and to estimate the relative importance of
the different components we turn to the effective onebody potentials. These are derived in exactly same
way as the one-body PNC potentials using eq. (7).
For charge-symmetric cores, i.e., cores with an equal
number of neutrons and protons, the matrix elements
of <r_Tj-r2 are zero, and matrix elements of o_r+
and v + r i are equal aAer summation. Thus, when
N - Z there is no T = 0 contribution to P.T-violation.
Futhermore, p-exchange interaction gives no
contribution for any isospin channel. For chargenonsymmetric cores (N * Z) these terms give a finite
contribution, but generally small. The vector meson
exchange cortrfcutions to P,T-vioIation are about two
orders of magnitude smaller that the T= 1 x-exchange
matrix elements. This is in sharp contrast to the
84
-(!)'
g M NN
(12)
Here it is assumed that P-violalion occurs primarily
through isoscalar (/ = 0) p-exchange characterized
by the coupling constant
which is related
to the counting constant F0, used in eq (1) by,
F
o>
=-g'$lNgpNNf2-
The ratio * has been evaluated [21] as a function of
nuclear mass assuming a single nucléon in a closedshell-plus-one configuration. The magnitude of * is
found to be about 5, and to display very little mass
dependence. Griffiths and Vogel [22] have also
calculated * for specific rare-earth nuclei, using the
quasipaiticle random phase approximation. They find
a very similar range of values. These results are
significant because they suggest thai the ratio of the
P,T-violating to P-violating amplitudes is
approximately independent of nuclear structure. Thus,
knowledge of the magnitude of * allows an estimate
of <K'*-J> from a measurement of (VP).
There has been only one experimental result on P,Tv iolation in 7-decay. This is from a study of the decay
of the (polarized) 8 "(1.142 MeV) metastable state
of "°Hf to Ihe 6 + (0.641 MeV) stale. The transition
exhibits an unusually large P-violating effect through
a forward-backward asymmetry (1.7%) and circular
polarization ( 0 2 %) of the emitted 7-rays. The effect
is an E2-E3 interference. If | A) is a P-mixed
and P,T-mixed stale (eq. (9)), the 7-ray transition
I A) — I B), exhibits a P.T-violating effect
proportional to
V . r 'bn
<fl||xL||/J> '
(13)
where x ' L' is the irregular mukipole available due
to P,T-violalion while tL is the mukipole present in
the absence of VF + VF T. The P-violaling effect in
Ihe same transkion is proportional to
The measuremerk in
bn{f\E2\i)
Fe<f\E2\i> '
,80
Hf yielded
-0.7±0.6
(15)
TTiis implies a limk on the PT-coupling constant
Ig^AW I <3.8 x 10" 6 /«. However, Ihe senskivky
of the experiment would have to be improved by four
orders of magnitude in order to improve the limk on
g r N N set by the dipole moment of 199Hg.
P.T-violalion can also be probed by study of the
transmission of polarized neutrons through polarized
nuclear targets [23]. These experiments are an
extension of the neutron transmission measurements
on unpolarized targets. In (he case of polarized targets,
the fractional difference of the resonance cross
sections for neutrons polarized parallel and aikipaiellel
to their momentum, P p r = a l - t f l / a l + a l , implies
simukaneous P- and T-violalion. The P.T-violating
asymmetry arises through a term in the scattering
amplkude proportional to a- (A x j ) . Hereof and a I
are the total scattering cross-sections for neutrons
polarized parallel and antiparellel to (k xj), a and A
are the neutron spin and momentum and J is the target
spin.
In a two-stale mixing approximation, the ratio of the
P.T-violating to P-violaling asymmetries in the
neutron measuremetls is given by
X=
P f T
»
7T
w v ' w " «ANN
- ^ -
06)
where ^ and \fip are compound nuclear s- and
p-wave resonance wave functions. The neutron
transmission experiments are most senskive to the
isovector coupling P.T-violating interaction, since k
is probed by all the nucléons. Combining the present
limk on g ^ N with the calculated value of k implies
that the required accuracy is about PriJ Pp - 10" 3 .
Finally, we consider the T-violating P-conserving
(TVPC) NN potential. In the case of the TVPC
interaction, the form of the meson-exchange potential
has been shown by Simonious [24] to be severely
constrained. No x-exchange or p°-exchange is
allowed; Only p± and A, (or heavier) mesons can
contribute. The At meson is considerably heavier
than the p, and so ks contributions are strongly
damped by the short-range NN correlations. The pexchangeT-violaling potential, which generates only
an isovector potential, is given by [24]
vivre
_
[nx^]3
(17)
Here / - r 12 x
g p is the normal strong
pMV coupling, and g„ is a dimensionless ratio of
the TVPC coupling to gp. The form of TVPC
potertial implies that neutrons only interact wkh
protons. Futhermore, in the case of charge symmetric
cores ( N - Z ) , there is no cortribution to the one-bod)
potential form the core nucléons. Thus, only a few
valence nucléons can contrtoute to a TVPC
observable.
The most stringent limks on g„ come from an
analysis [ 25 ] of the experimental limks on Ihe electric
dçole moment of l99 Hg and of the neutron. These
implies | g ^ | s 9 . 4 X 10~ 2 .
French elal. [ 12] studied the sensitivky of spectral
fluctuations and strength functions in the compound
mclear regime to a time-reversal non invariant term
in the nuclear Hamiltonian. The senskivky to spectral
fluctuations arises because a TVPC Hamikonian leads
to stronger level repulsion than a symmetryconserving Hamiltonian. In the case of strength
functions, one can search for deviations from the
Porter-Thomas distribution generated by a timereversal invariant Hamikonian. The d*a set studied
included 1702 levels in 32 nuclei. Since the analysis
of compound nuclear resonances require enormous
model spaces, French tt al. used their spectral
averaging formalism for this analysis. The resuks
were expressed in terms of a coefficient a T , which
is the ratio of typical TVPC NN matrix elements In
those of the symmetry-conserving shell model
involves mixing between several states, have yet to
achieve the required accuracy to extract reliable
coupling constants.
T A B L E II. Isovector ir-exchange, Vp,r, and isoscalar p-exchange, Vp, m a t r i x e l e m e n t s evaluated
for a r losed-shell-plus-one configuration for six choices of t h e closed-shell core. T h e weak interaction
coupling c o n s t a n t s are ff^jyv =
* 1 0 _ U and
= —11.4 X 1 0 - 7 .
160
N=8
Z=8
Op -
< v,
1
> in e V x 1 0 " 4
Vp > in e V
0j
1 084
1513
, 0
Ca
N=20
Z = 20
90
Zr
N = 50
Z=40
138
Ba
N=82
Z=56
1.
2p - 2 3
2p - 2s
0 875
1 550
0.708
1.535
0.779
1 576
1p -
208pb
232Th
N=126
Z=82
N=142
Z=90
3s
3p - 3>
0.608
1 581
0.633
1 600
3p -
In heavy nuclei, where the parity violation between
compound resonances is analyzed within the statistical
shell model, the present indications are that the models
need to be extended. To date statistical calculations
have been confined mainly to studies of positive parity
operators. For most of these, the strength function
of the operator is determined by the same model space
that determines the level density. In the case of
negative parity states, the level density is determined
by the so-called intruder state. The ittruder stale is
the state of maximum J from the next highet shell
which is pulled down one shell by the very strong
spin-orbit interaction in heavy nuclei. The angular
momentum difference between the opposite-parits
irtruder orbital and all other orbitals in the shell means
that the intruder cannot contribute to the one-bod>
PNC matrix elements. Thus, if the calculations arc
carried out in the model space that determines the
spectral level density, the PNC matrix elements will
arise solely from the valence t wo-body part of PNC
interaction and matrix elements of the one-bod)
potential (eq. 7) will be identically zero. This suggets
the need for extensions of the standard model space
and it remains to be seen whether the statistical model
will be able to reproduce the giant resonance structure
of the one-body operators.
T A U L E III. Weak P N C coupling c o n s t a n t s . T h e theoretical values and range are from t h e q u a r k
model calculations of D e p l a n q u e s et al. [4] and t h e e x p e r i m e n t a l values are from t h e analyses of
Adelberger a n d H a x t o n [6]
Coefficient
F.
Fo
Best value( 1 0 ~ 6 1
Theory
Reasonable range ( 10"6 )
Theory
Best v a l u e d 0 - 6 )
Fit t o Expt
1.08
1 59
0:2.71
-1 59:4 29
<0-1
0 8
interaction. The limit at the 99% confidence level is
| a r | <2 x 1 0 - 3 . Haxton « al. [25] have related
aT to the coupling constant gpNN in 199 Hg by
comparing matrix elements of Fj v ' > c with matrix
elements of the residual strong interaction in a shell
model calculation. They find that the limit on a T
implies | |
£2.5.
There has been one published measurement of a Tviolating P-conserving correlation in the scattering
of polarized neutrons on aligned l65 Ho targets.
These measurements searched for a dependence of
the forward elastic-scattering amplitude on the Tviolating P-conserving correlation term (a-J x k)
(J k). Here, J and a are unit vectors along the axes
of the target alignment and neutron polarization, and
k is the direction of the incident neutron beam.
The neutron scattering experiment was analyzed in
terms of the T-violating potential by Engel etal. [26]
who derived a TVPC optica) potential for the neutronnucleus potential, starting from the p-exchange twobody potential. In this way they obtained limits on
!>PNN- This result indicates the need for an order
of magnitude better accuracy in the measurements in
order to improve on the limits set by the electric dipole
searches. It is anticipated that an improvement of
~ 150 can be achieved.
FUTURE DIRECTIONS
While much progress has been made in our attempts
to understand nuclear parity violation, a number of
open questions remain. The original motivation of the
program was to extract information on the
fundamental weak interaction between the quarks
from the PNC meson-nucleon coupling constants.
However, this hope has been blighted by theoretical
difficulties at the particle physics level. In principle,
the weak meson-nucleon amplitudes, and hence the
corresponding coupling constants, can be calculated
starting with the standard electroweak interaction
between quarks. However, the elementary If and Z
exchange occuring inside the weak meson-nucleon
vertex are dressed by hadronic effects in a sufficiently
complicated way that the estimated [4] values for
the coupling constants are assigned large uncertainties.
The "best values" and "reasonable range" for the
two PNC coupling constants FR and F0, resulting
from the quark model calculations, along with the
values obtained [6] from thebest fit to experiment,
are tiven in Table III. The allowed range on the
theoretical values for the coupling constants means
that even very precise experimental determinations
of FR and F0 will not provide constraints on the
fundamental weak interaction between quarks.
The calculations require the evaluation of threehadron matrix element of a four quark-operator,
<M?V1| N). An improvement in the calculations
to the level that would allow a direct connection
between the meson-nucleon potentials and the quarkquark weak interaction is unlikely to be achieved in
the near future.
On the nuclear physics side, the outlooks is much
more optimistic. Studies of parity violation have
pushed models of the nucleus to new limits and,
indeed, have become the primary motivation for
extensions of statistical treatments of chaotic spectra
in nuclei. In the lighter nuclei, around mass 18, stateof-the-art shell model calculations have been carried
out to analyze the PNC effects. As shown in Fig. 2,
the PNC matrix element between a state | 7 + > and
a closely lying state | J~) is only a very small
fraction of the total PNC strength to all states | J ~ 1 >.
Thus, very detailed knowledge of the nuclear wave
functions is needed to obtain a reliable prediction of
the matrix elements. In particular, at least 2iui of
excitation must be included in the model space and
spurious certer of mass excitations must be eliminated
exactly. Structure theorists have taken advantage of
the rapid advances in computer technology and
modern shell model codes can now handle very large
model spaces. Recently, these advances provided the
first muki-Koj calculation of 2 , Ne, which in turn
provided the first set of consistent values for FR and
F0 for the PNC measurements in the three paritydoublet cases. Calculations in light nuclei, where the
parity mixing is not confined to a doublet but instead
New experiments are planned to measure parityviolating asymmetries in polarized-neutron scattering
over a wider range of nuclear masses. In contrast to
heavy nuclei, analyses of the PNC matrix elements
in light nuclei show that the one-body part of the
interaction dominates there. A current topic of interest
is the issue of how the role of the one-body versus
two-body parts of the PNC irteraction vaty as the
intruder orbital is lowered in energy. Ideally, one
would like to measure the effects in a common nucleus
that can be calculated both within the regular shell
model and the statistical shell model.
Studies of P-odd T-odd correlaions in the nucleus
have proved less sensitive than searches for electric
dipole moments. To data gamma ray correlations are
simply too insensitive to provide meaningful limits
on the PT-voilating coupling constants. However,
there may exist transkions where enhancements
arising from special nuclear structure effects resuh
in a large asymmetry. The most likely candidates
would be expected in deformed nuclei and further
theoretical work is needed here. Estimates for the
required sensitivity in the neutron transmission
experiments suggest a need for an accuracy of 10
- 1 0 - 6 for the PpjJPp ratio. It remains to be seen
whether this accuracy can be achieved. Significant
improvements on the T-odd P-even correlations in
neutron scattering experiments are anticipated in the
near future. These are expected to provide improved
limits on the corresponding coupling constant.
REFERENCES
[ IJ l.S. Towner and J.C. Flardy, in The Nucleus as a
Laboratory for Studying Symmetries and Fundamental
Interactions, eds., E M. Henley and W.C. Haxton
(World Scientific, Singapore. 1955) to be published.
[2] G. Barton, Nuovo Cimento 1» 512 (1961).
(3) E M. Henley. Ann. Rev. Nucl. Sci. 19. 367 (1969).
[4J Bertrand Deplanques, John F. Donoghue, and Barry
R. Hal stein. Anns. Phys. 124. 449 (1980).
La Physique au C a n a d a
m a r s à avril 1 9 9 6
85
OUTFLOWS FROM SPIRAL GALAXIES
J u d i t h A . I r w i n , Dept. of Physics, Q u e e n ' s U n i v e r s i t y , Kingston, K7L 3 N 6 , Canada, i r w i n @ a s t r o . q u e e n s u . c a
by
SPIRAL G A L A X I E S — A V I E W T H R O U G H
THE TELESCOPE EYEPIECE
W h e n m o s t of us envision a " g a l a x y " , w e
tend t o think of g i a n t spirals, b o t h
s t r u c t u r e d and beautiful, o f t e n displayed
with
prominence
on t h e c o v e r s
of
a s t r o n o m y t e x t s (Fig. 1). The image is at
optical w a v e l e n g t h s , as if peering t h r o u g h
a v e r y p o w e r f u l telescope on a clear,
m o o n l e s s night. W e see a bright f l a t t e n e d
disk c o n s i s t i n g of = 1 0 " stars t o o c r o w d e d
over t h e field of v i e w t o be resolved
individually. Prominent spiral arms w i n d
t h r o u g h t h e disk emerging f r o m a g l o w i n g
central bulge, and around the disk is a
roughly spherical halo region sparsely
populated w i t h globular star clusters, each
one c o n t a i n i n g perhaps half a million stars.
W i t h careful o b s e r v a t i o n , w e can discern
n u m e r o u s details, b i f u r c a t e d spiral a r m s ,
subtle colour d i f f e r e n c e s , dark dust lanes
threading along the a r m s or reddish ionized
h y d r o g e n (HID regions associated w i t h the
b r i g h t e s t , h o t t e s t stars. The v i e w is
b r e a t h t a k i n g , and not at all incorrect.
Indeed, s o m e might argue that this picture
is q u i t e adequate, given that most of the
observable mass of the g a l a x y is locked up
in stars w h i c h emit black body radiation at
p r e d o m i n a n t l y o p t i c a l w a v e l e n g t h s . But
t h e r e ' s more g o i n g on here t h a n meets the
eye.
Fig. 1
The nearby galaxy, M 3 1 (The
Andromeda Galaxy) and its t w o
small companions. The image is at
optical wavelengths in w h i c h the
emission is predominantly
from
stars. Image available through the
home page of "Students for the
Exploration and Development of
Space" (http://seds.lpl.arizona.edu/).
Decades of s t u d y of our h o m e Galaxy, the
M i l k y W a y , have provided us w i t h a v i e w
w h i c h is v e r y similar t o the d e s c r i p t i o n
above, the sun and its planets near an
outer spiral a r m orbiting the center of the
Galaxy w i t h a period (a f e w x 10 e yr)
d i c t a t e d by the Galactic mass d i s t r i b u t i o n .
A n o p t i c a l 3-D m a p of t h e M i l k y W a y ,
however,
becomes
sketchier
with
increasing d i s t a n c e f r o m t h e sun, due t o
o b s c u r a t i o n by interstellar d u s t . Indeed, if
w e look along the plane of the M i l k y W a y
(seen as the faint band of light s t r e t c h i n g
across the sky), the stars that are visible
are only the relatively nearby ones, out t o
distances of a f e w kpc (1 kpc = 3.1 x
1 0 ' 9 m) c o m p a r e d to the 8 kpc distance t o
t h e Galactic C e n t e r ' . Starlight is scattered
and reddened by dust by the same
processes w h i c h d i m and redden light
f r o m the setting sun. Since interstellar
but o c c u p y large filling f a c t o r s and
cover most of the observable s k y , t h o u g h
w i t h decreasing intensity as a f u n c t i o n of
distance f r o m the M i l k y W a y plane. They
are also tracers of energetic phenomena
and the c o s m i c ray c o m p o n e n t a l l o w s us
to map out the s t r u c t u r e and d i r e c t i o n
of the Galactic magnetic field f r o m
observations of s y n c h r o t r o n polarization.
grain radii tend t o be in the range, i a f e w
hundredths to a f e w t e n t h s of a / / m ,
h o w e v e r , w a v e l e n g t h s s u f f i c i e n t l y longer
t h a n this particle size w i l l propagate over
scales of Galactic proportion, essentially
without
interaction.
Consequently,
observations at
m m , c m , and some
infrared w a v e l e n g t h s provide us w i t h
useful probes of the large scale s t r u c t u r e
of the Galaxy.
The
total
ISM
mass
constitutes
a p p r o x i m a t e l y 1 0 % of the g a l a x y ' s t o t a l
observable mass. M o s t of this mass is
split roughly equally b e t w e e n t w o neutral
components.
One is neutral atomic
hydrogen
(HI),
which
is
ubiquitous
t h r o u g h o u t the Galaxy and detectable
t h r o u g h observations of the g r o u n d s t a t e
hyperfine t r a n s i t i o n at l) =
1420.406
M H z . HI (T = 1 0 0 K) is seen in cloud
s t r u c t u r e s , in w i s p y f i l a m e n t s , arcs and
plumes, and as s m o o t h w a r m e r intercloud
gas. It is e x t r e m e l y useful for mapping out
the large-scale r o t a t i o n of the Galaxy f r o m
Doppler s h i f t s of this spectral line. The
second c o m p o n e n t is molecular h y d r o g e n
(H 2 ) w h i c h congregates in denser clouds
and is more c o n c e n t r a t e d t o w a r d s the
g a l a x y ' s plane t h a n the HI. There does not
appear t o be any intercloud H 2 , since the
radiation field in l o w d e n s i t y regions
b e t w e e n clouds is capable of dissociating
the h y d r o g e n molecule. Interstellar dust is
correlated spatially w i t h dense molecular
clouds and it is believed that molecules
f o r m m o s t e f f i c i e n t l y on the surfaces of
these grains.
U n f o r t u n a t e l y , H ? has no
dipole
moment
and
is
therefore
undetectable under normal interstellar
2
conditions .
Therefore, the q u a n t i t y of
molecular h y d r o g e n is normally inferred
(with
some
controversy
as t o
the
c o n v e r s i o n factor) f r o m observations of the
next m o s t abundant molecule, c a r b o n
m o n o x i d e , w h i c h is collisionally excited by
the H 2 .
CO has several accessible
rotational transitions in the m m and
s u b - m m regimes (e.g. J =
1 —» 0
corresponds t o v = 1 1 5 . 2 7 1 GHz).
THE INTERSTELLAR " V A C U U M " — A
BROADENING PERSPECTIVE
W h e n a radio telescope is pointed at the
M i l k y W a y , the resulting v i e w is quite
d i f f e r e n t f r o m the optical picture described
above.
Stars, being w e a k e m i t t e r s at
radio w a v e l e n g t h s , disappear f r o m v i e w
and instead, depending on the tuned
f r e q u e n c y , the sky is filled w i t h emission
f r o m the " v a c u u m " b e t w e e n the stars.
Interstellar space is filled w i t h numerous
c o m p o n e n t s (including d u s t ) , collectively
k n o w n as t h e interstellar m e d i u m (ISM).
The ISM is not u n i f o r m , rather its
c o n s t i t u e n t s o c c u p y v o l u m e s of space of
various size and cover m a n y orders of
m a g n i t u d e in d e n s i t y and t e m p e r a t u r e —
f r o m hot " c o r o n a l " gas w i t h densities as
low
as
0.001
particles
cm3
and
t e m p e r a t u r e s as high as = 1 0 6 K t o
molecular cloud cores w i t h densities as
high
as
1078
particles
cm3
and
t e m p e r a t u r e s as l o w as =>10 K. A l t h o u g h
the densest of clouds is still orders of
m a g n i t u d e rarer t h a n the best v a c u u m
attainable in earth-based laboratories,
w h e n integrated over the e x t r e m e l y large
distances of interstellar space, c o l u m n
densities can be considerable (e.g. 10 22
particles c m 2 for neutral a t o m i c hydrogen)
and
the
emission
is
often
easily
detectable.
M u c h of the volume of the ISM is taken
up by hot, l o w d e n s i t y ionized hydrogen
(called coronal gas) and by l o w density
c o s m i c rays w h i c h w e r e accelerated in
high energy regions like supernova shock
waves.
The
ionized
hydrogen
is
detectable
from
its
Bremsstrahlung
e m i s s i o n in the s o f t X-ray regime, w h i c h
requires
satellite
observations.
Ultra-relativistic (e.g. y = 1000) c o s m i c
ray electrons spiral around
Galactic
magnetic field lines and can be d e t e c t e d
by the subsequent s y n c h r o t r o n emission
w h i c h is radiated as a
continuous
s p e c t r u m in the c m - w a v e l e n g t h radio
regime. These t w o c o m p o n e n t s c o n t r i b u t e
a negligible a m o u n t of mass t o the ISM,
'interstellar absorption varies strongly w i t h position in the Galactic plane.
Under some conditions, e.g. in regions close t o stars, molecular hydrogen can attain temperatures
of several thousand K in w h i c h case some vibrational transitions are observable in the infra-red.
2
86
Physics in Canada
M arch/Aprill 9 9 6
So far as w e k n o w , this d e s c r i p t i o n of the
ISM in our o w n Galaxy is applicable t o
m o s t other spirals, t h o u g h it is d i f f i c u l t t o
d i s c e r n the detailed s t r u c t u r e of the
various c o m p o n e n t s in other galaxies due
t o lack of s u f f i c i e n t spatial resolution at
the greater distances.
There are also
d i f f e r e n c e s b e t w e e n galaxies, h o w e v e r ,
especially in the relative quantities of the
various c o m p o n e n t s , and in the agitation
they
are
experiencing
from
internal
energetic events.
THE VIOLENT INTERSTELLAR M E D I U M
Recently,
our
understanding
of
the
interstellar m e d i u m (ISM) in our o w n and
other spiral galaxies has undergone a
d r a m a t i c change. T w e n t y - f i v e years ago,
the ISM w a s t h o u g h t t o consist o n l y of
quiescent neutral h y d r o g e n in t w o phases
(cool cloud and w a r m intercloud gas)
w h i c h w e r e in pressure equilibrium (Field,
Goldsmith
and
Habing
1969).
As
satellite-based telescopes w e r e launched,
this v i e w had t o be m o d i f i e d t o include the
hot X - r a y e m i t t i n g c o m p o n e n t , p r e s u m a b l y
supplied t h r o u g h supernova explosions
(Cox and S m i t h 1 9 7 4 , M c K e e and Ostriker
1977).
With
continually
improving
Fig. 2
GALAXY OUTFLOWS
It has been k n o w n since the early d a y s of
radio a s t r o n o m y that some
galaxies
experience o u t f l o w s , but these o u t f l o w s
are in the f o r m of n a r r o w jets originating
f r o m " a c t i v e galactic nuclei" or A G N s ,
m o s t likely associated w i t h a s u p e r m a s s i v e
black
hole at the g a l a x y ' s
center.
A l t h o u g h spectacular, s u c h o u t f l o w s w e r e
only seen in distant elliptical galaxies and
w e r e not observed in relatively nearby
The edge-on nuclear starburst galaxy, NGC 3 6 2 8 , w i t h optical emission s h o w n in grey scale
and overlaid contours depicting X-ray emission due t o hot ionized gas. Adapted from
Fabbiano et al. ( 1 9 9 0 ) , copyright American Astronomical Society, reproduced w i t h
permission.
o b s e r v a t i o n s , especially at non-optical
w a v e l e n g t h s , w e n o w see the ISM as
c o m p l e x and m u l t i phased as described
above. H o w e v e r , far f r o m q u i e s c e n t , it is
n o w u n d e r s t o o d t o be f r o t h y and seething,
undergoing violent a c t i v i t y , and possibly
experiencing o u t f l o w s as gas is d r i v e n
a w a y f r o m the disk into the halo region
around it (e.g. N o r m a n and Ikeuchi 1 9 8 9 ,
or papers in Bloemen 1 9 9 1 ) .
The realization that there is a d y n a m i c
disk-halo relationship in our o w n Galaxy
crystallized
with
the
discovery
of
expanding HI shells and supershells of kpc
scale e x t e n d i n g over the d i s k - h a l o b o u n d a r y
("Heiles Shells"; Heiles 1 9 7 9 ,
1984).
Since this early w o r k , other evidence for
disk-to-halo o u t f l o w s has a c c u m u l a t e d ,
including expanding molecular (i.e. CO)
shells in the Galactic Center region (Oka et
al. 1 9 9 5 ) , and features over the disk in
various
wavebands
which
spatially
correlate w i t h the Heiles Shells (e.g. Koo
et al. 1 9 9 1 ; Waller and Boulanger 1 9 9 3 ;
Reach et al. 1 9 9 3 ) . The input energies
implied by the HI shell masses (obtained
f r o m the l u m i n o s i t y of the spectral line)
and e x p a n s i o n velocities (obtained by the
Doppler shift of the spectral line) c a n be
considerable — energies up t o = 10 6 b erg
are not out of the ordinary.
spirals. Since t h e 1 9 8 0 s , h o w e v e r , there
have also been discoveries of (wider
opening angle) bipolar o u t f l o w s f r o m the
nuclei of spiral galaxies. Some of these
nuclear o u t f l o w s fall into the l o w e r
l u m i n o s i t y end of the A G N c a t e g o r y , but
not all. It appears t h a t galaxies w i t h o u t
A G N but w h i c h are experiencing strong
nuclear " s t a r b u r s t s " can also produce a
bipolar o u t f l o w .
A starburst occurs w h e r e v e r there is an
unusually high massive (e.g. i 5 - » 8 M e )
star f o r m a t i o n rate. M a s s i v e stars live for
a relatively short (e.g. s 1 0 ' years) t i m e
and
end
their
lives
in
supernova
explosions.
Since the star f o r m a t i o n
process itself can occur over t i m e s c a l e s
longer t h a n this, star births and star deaths
can proceed at the same t i m e .
Star
formation
activity
(and
therefore
supernova a c t i v i t y ) can be enhanced in the
nucleus if, for example, a
passing
companion galaxy
perturbs the
gas
d i s t r i b u t i o n , resulting in gas transfer
t o w a r d s the center. The build up of gas
invokes accelerated star f o r m a t i o n and a
resulting " b u r s t " of a c t i v i t y f r o m the
c o l l e c t i v e c o n t r i b u t i o n s of m a n y individual
supernova explosions. Given t h a t initial
o u t f l o w velocities f r o m supernovae are of
order 1 0 , 0 0 0 k m s the consequences can
be significant. In some cases, the result is
bipolar nuclear o u t f l o w along the r o t a t i o n
axis of the g a l a x y as the hot ejecta takes
the path of steepest decreasing pressure
gradient a w a y f r o m the nucleus. A good
example of bipolar o u t f l o w f r o m a nuclear
starburst is the g a l a x y , NGC 3 6 2 8 (Fig. 2)
in w h i c h the o u t f l o w i n g hot gas is visible
as soft X - r a y e m i s s i o n far f r o m the plane.
Starburst galaxies are more n u m e r o u s t h a n
A G N in the nearby universe and potentially
present us w i t h a clearer v i e w of the
physical processes w h i c h are involved in
driving such outflows.
The first clear evidence for o u t f l o w s f r o m
the disks of spirals other t h a n the M i l k y
Way
came
from
observations
of
NGC 3 0 7 9
in w h i c h
HI shells
and
supershells similar t o the "Heiles Shells" of
our o w n Galaxy w e r e d e t e c t e d ( I r w i n and
Seaquist 1 9 9 0 ) . There are n o w a number
of other galaxies for w h i c h there is g o o d
evidence for disk-to-halo o u t f l o w .
Of
those displaying HI shells, the c o m p l e t e
(but g r o w i n g ) list is still probably less t h a n
a dozen (see examples in I r w i n 1 9 9 5 ) .
This number increases if w e also include
galaxies w h i c h display radio c o n t i n u u m
(from s y n c h r o t r o n emission) t h i c k disks or
halos (e.g. H u m m e l , Beck, and D e t t m a r
1991).
A g o o d example of a galaxy
w h i c h displays b o t h HI disk halo arcs as
w e l l as a d r a m a t i c radio c o n t i n u u m halo is
NGC 5 7 7 5 (Fig. 3). The halo around this
galaxy is so large (= 16 kpc radius in
projection) that the g a l a x y resembles an
elliptical in this w a v e b a n d . At the same
t i m e , considerable s t r u c t u r e is observed in
the o u t f l o w features, potentially providing
clues as t o the mechanism(s) t h a t f o r m e d
t h e m . These o b s e r v a t i o n s suggest that gas
(both non-relativistic and relativistic) can
be expelled f r o m spiral g a l a x y disks w h e r e
the star f o r m a t i o n rates are considerably
more m o d e s t t h a n in the nuclei.
The
q u e s t i o n arises, then, are the disk o u t f l o w s
also a result of processes related t o
m a s s i v e star f o r m a t i o n ?
There is good evidence t o suggest that the
disk o u t f l o w s are indeed related
to
s t a r b u r s t i n g , but starbursting alone does
not appear to be s u f f i c i e n t to account for
the observed features. In the M i l k y W a y ,
some of the Heiles Shells do appear t o be
correlated w i t h active sites of
star
f o r m a t i o n and m o s t of the theoretical w o r k
pursued t o date has f o c u s e d on modelling
the s t r u c t u r e s e x p e c t e d f r o m a rapid input
of supernova kinetic energy (e.g. Tomisaka
1 9 9 1 ) . H o w e v e r , a d i f f i c u l t y arises w h e n
the largest HI shells are considered.
O b v i o u s l y , the input energy m u s t be at
least as high as the expansion energy of
the shell (up t o 1 0 6 6 e r g ) . W h e n c o n v e r t e d
to
the
required
number
of
input
supernovae, the result can be more t h a n
4
10 .
This s t r e t c h e s the starbursting
scenario severely, since most associations
of hot, s u p e r n o v a - p r o d u c i n g stars in our
o w n Galaxy are t h o u g h t t o c o n t a i n < 10 2
stars, t h o u g h s o m e m a y be more populous.
M o r e o v e r , even if the energy is available,
large scale HI features can only be f o r m e d
if the scale height of the disk is also
unrealistically large (e.g. Heiles 1 9 9 0 ) .
This "energy p r o b l e m " has led some
87
researchers t o seek other explanations for
the HI supershells.
In the M i l k y W a y , there appear t o be
connections between a f e w
outflow
f e a t u r e s and " h i g h v e l o c i t y c l o u d s " . These
Recent observations of HI supershells in
t w o undisturbed, isolated spiral galaxies
(Lee and I r w i n , in preparation; Giguere and
I r w i n , in preparation) n o w indicate t h a t the
cloud impact model is an unlikely one for
these galaxies. The star f o r m a t i o n rates in
03 49
48 -
47 ~
©
1»
CD
m
46
z
o
F
45
<
z
Zj
O
Ul
a
44
43
42 -
14 51 35
Fig. 3
30
25
20
15
RIGHT ASCENSION (B1950)
05
The edge-on galaxy, NGC 5 7 7 5 , and its interacting face-on companion, NGC 5 7 7 4 , t o the
north-west (i.e. upper right). The centers of both galaxies are marked w i t h crosses.
Grayscale denotes the neutral hydrogen emission w h i c h is strongest in NGC 5 7 7 5 along a
narrow south-east t o north-west path and corresponds roughly t o the stellar disk of this
edge-on galaxy. Fainter neutral hydrogen emission can be seen extending away f r o m this
disk in the f o r m of arcs, plumes and extensions. Contours represent radio continuum
emission f r o m the synchrotron process, forming an extended flattened halo w i t h considerable
substructure.
clouds f o r m part of a cloud s t r e a m w h i c h
s t r e t c h e s b e t w e e n the M i l k y W a y and its
nearby c o m p a n i o n galaxies, the Magellanic
Clouds, as a result of a tidal interaction.
These c o n n e c t i o n s , as w e l l as the energy
problem described above have led t o the
Cloud Impact model for the f o r m a t i o n of HI
shells in the M i l k y W a y (see r e v i e w by
Tenorio-Tagle and Bodemheimer 1 9 8 8 ) ,
and n o w in other galaxies as w e l l (e.g.
NGC 4 6 3 1 , Rand and Stone 1 9 9 5 ) . A s the
name suggests, the HI supershells are
f o r m e d f r o m the i m p a c t of clouds o n t o the
Galactic disk, in w h i c h case the shell
energy is d i c t a t e d by the infalling cloud
mass and the infall v e l o c i t y . This a l l o w s
for m u c h larger input energies since the
infalling cloud c a n be a tidal shred f r o m the
interacting
galaxy
w i t h an (almost)
arbitrarily large mass. Of course, appealing
t o c l o u d i m p a c t s as the source of disk-halo
supershells requires t h a t the g a l a x y either
be undergoing an i n t e r a c t i o n or at least
have c o m p a n i o n s nearby as a potential
source of external clouds.
88
10
Physics in Canada
M arch/Aprill 9 9 6
these galaxies exceed that in our o w n ,
and it is therefore possible t h o u g h not
observationally proven that very large
numbers
of
supernovae
may
also
congregate
in
individual
clusters.
H o w e v e r , the d i f f i c u l t y in producing HI
supershell
structures
remains.
For
example, in one case, the size of the HI
shell is fully half the radius of the g a l a x y ,
far in excess of any reasonable scale
height.
It is therefore w o r t h w h i l e t o
search for s o m e additional source of
energy, besides supernovae, t o explain the
observations. Perhaps the disk and halo
are coupled in s u c h a w a y that rotational
shear can be c o n v e r t e d into vertical
m o t i o n . Further theoretical w o r k , possibly
in the realm of non-linear magnetoh y d r o d y n a m i c s (e.g. Parker instabilities),
appears t o be required.
THE SIGNIFICANCE A N D CONSEQUENCES
OF O U T F L O W S
W h i l e only a " h a n d f u l " of galaxies s h o w i n g
evidence for o u t f l o w s have so far been
identified, I w o u l d c o n t e n d that t h i s is
largely because of selection e f f e c t s . It is
important t o observe galaxies w h i c h are
highly enough inclined that the disk can in
fact be separated spatially f r o m the halo
region around it. So far, f e w studies have
s y s t e m a t i c a l l y c o n c e n t r a t e d on galaxies
w i t h this orientation. Because the features
tend to be faint, it is also necessary t o
integrate long enough t o o b t a i n g o o d
signal-to-noise. The radio c o n t i n u u m halo
observed around NGC 5 7 7 5 (Fig. 3), for
example, w a s only d e t e c t e d by c o m b i n i n g
data
from
three separate
observing
sessions, for a t o t a l of 6 hours of on-source
t i m e using the V e r y Large A r r a y ( V L A ) radio
telescope near Socorro, N e w M e x i c o .
Neutral h y d r o g e n observations also tend t o
be t i m e c o n s u m i n g , b o t h in the c o l l e c t i o n
and analysis of the data. A single g a l a x y
requires
an i n t e g r a t i o n
time
of
a p p r o x i m a t e l y 12 hours using t h e V L A and
processing and analysis m u s t proceed on
" c u b e s " of data since a m a p is generated
for every spectral channel. The r e w a r d s ,
however,
are w e l l
w o r t h the
time
i n v e s t m e n t . In a survey of 17 edge-on
galaxies in the radio c o n t i n u u m , it w a s
f o u n d that virtually every galaxy s h o w e d
radio c o n t i n u u m extensions beyond the
optical boundaries of the disk (Sorathia and
I r w i n 1 9 9 5 , in preparation; Sorathia 1 9 9 4 ) .
It is entirely possible then, that at some
level, o u t f l o w s are a c o m m o n characteristic
of all spiral galaxies w h i c h are a c t i v e l y
undergoing star f o r m a t i o n .
W h a t is the u l t i m a t e f a t e of the expelled
gas? Does the gas cool and fall back to the
disk again like a "Galactic Fountain" as first
suggested some 2 0 years ago (Shapiro and
Field 1976) or does it leave the galaxy
altogether, f l o w i n g i n t o i n t e r g a l a c t i c space?
For galaxies like NGC 5 7 7 5 (Fig. 3) the
radio c o n t i n u u m e m i s s i o n extends so far
f r o m the plane (i.e. = 16 kpc) t h a t the halo
resembles an oblate spheroid in projection.
The existence of halo s u b s t r u c t u r e far f r o m
the plane implies that d y n a m i c a l processes
are still at w o r k at v e r y large scale heights,
suggesting that at least s o m e mass loss is
likely occurring.
On the other hand,
observations of X - r a y emission f r o m the hot
halo of the g a l a x y , NGC 8 9 1 , suggest t h a t
this t h e r m a l gas is bound t o the galaxy
(Bregman and Pildis 1 9 9 4 ) . Some galactic
circulation models suggest that either
scenario is possible, depending on the
density of the ISM and the level of energy
input (e.g. N o r m a n and Ikeuchi 1 9 8 9 ) .
A s y e t , w e have no direct observational
measure either of mass loss or mass
circulation rates f r o m a galaxy disk. Some
theoretical e s t i m a t e s place a mass loss rate
for our o w n Galaxy of order = 1 M o yr '
(Vôlk 1 9 9 1 ) . Other galaxies are clearly
experiencing higher star f o r m a t i o n rates
t h a n the M i l k y W a y , suggesting an u p w a r d s
increase in the mass loss rate for t h e m . If
these e s t i m a t e s are c o r r e c t , t h e n over the
course of a single g a l a x y r o t a t i o n (a f e w x
10 8 years) the ISM, w h i c h c o n t a i n s a f e w
t i m e s 10 s M o could be s i g n i f i c a n t l y (i.e. at
levels i 1 0 % ) depleted. A f t e r a dozen
rotations, a naive extrapolation w o u l d have
the ISM t o t a l l y depleted. W i t h less gas
available t o f o r m stars, this alters our v i e w
of the star f o r m a t i o n h i s t o r y of the g a l a x y
and the global p r o g r e s s i o n of star f o r m a t i o n
in various m o d e l s . Indeed, our telescopic
v i e w of the g a l a x y , being d i c t a t e d by the
available s t a r l i g h t , is a p r o d u c t of these
processes.
A p a r t f r o m mass loss due t o o u t f l o w s ,
there is already a gas c o n s u m p t i o n
" p r o b l e m " in galaxies s i m p l y f r o m the
c o n v e r s i o n of gas into stars (Larson,
T i n s l e y , and C a l d w e l l 1 9 8 0 ) . That is, if
current star f o r m a t i o n rates (as e s t i m a t e d
f r o m o b s e r v a t i o n s of star f o r m i n g a c t i v i t y
in galaxies) are a s s u m e d t o be c o n s t a n t
w i t h t i m e , t h e n the same c o n c l u s i o n --- that
the ISM w i l l be depleted over t i m e s c a l e s
shorter than the age of the g a l a x y — is
reached.
A d d i t i o n a l m a s s loss f r o m
o u t f l o w s o n l y exacerbates this problem.
W h i l e it is n o w m o r e w i d e l y believed that
star f o r m a t i o n rates are not c o n s t a n t and
m a y even undergo c y c l e s of bursts, s o m e
researchers have s u g g e s t e d t h a t the ISM
m u s t be c o n t i n u a l l y supplied by s o m e (as
yet hypothetical)
source of
external
a c c r e t i o n , for e x a m p l e primordial material
left over f r o m the e p o c h of g a l a x y
f o r m a t i o n (Pfenniger and C o m b e s 1 9 9 4 ;
Pfenniger, C o m b e s and M a r t i n e t 1 9 9 4 ) .
Thus, a better u n d e r s t a n d i n g of the
l o n g - t e r m e f f e c t s of gas c o n s u m p t i o n and
m a s s loss are required in order t o address
c o n c e r n s of a c o s m o l o g i c a l nature.
If gas is being d r i v e n into intergalactic space,
it is also of interest t o consider w h a t e f f e c t s
s u c h o u t f l o w s w i l l have on the galaxian
environment.
Will these
outflows
d y n a m i c a l l y a f f e c t their nearby neighbours,
as s u g g e s t e d b y o b s e r v a t i o n s of a
c o m p a n i o n to the g a l a x y , NGC 3 0 7 9 ( I r w i n
et al. 1987)? To w h a t e x t e n t d o these
o u t f l o w s enrich the intergalactic m e d i u m
w i t h heavy e l e m e n t s f r o m supernova
ejecta? Is t h i s a s o u r c e of hot intergalactic
gas w h i c h is o b s e r v e d in some c l u s t e r s of
galaxies? Does this gas c o n t r i b u t e t o the
intergalactic a b s o r p t i o n lines ( m o s t l y Ly«)
seen against b a c k g r o u n d quasars (and
closer objects)? The i m p l i c a t i o n s of s u c h
a c t i v i t y are o n l y n o w being explored. It
seems likely, h o w e v e r , that our v i e w of
spiralgalaxies as the isolated stellar s y s t e m s
w h i c h grace the c o v e r s of t e x t b o o k s m a y
require s u b s t a n t i a l m o d i f i c a t i o n .
ACKNOWLEDGEMENTS
5.
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155, L149
6.
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8.
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Hummel, E., Beck. Ft., and Dettmar,
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Irwin, J . A . 1995, Pub. A. S. P., 107,
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89
lll-V S E M I C O N D U C T O R C H A R A C T E R I Z A T I O N FOR O P T O E L E C T R O N I C S
by
Carla J . M i n e r , A d v a n c e d T e c h n o l o g y Laboratory, Bell N o r t h e r n Research, O t t a w a , Ontario K1Y 4 H 7 , (e-mail: miner@bnr.ca)
ABSTRACT
Three of t h e specialized n o n - d e s t r u c t i v e
c h a r a c t e r i z a t i o n t o o l s developed t o m o n i t o r
t h e advanced materials used in the
f a b r i c a t i o n of high speed o p t o e l e c t r o n i c s
are
described,
namely,
scanning
reflectance s p e c t r o s c o p y (sRS), scanning
photoluminescence
(sPL)
and
double
c r y s t a l x-ray d i f f r a c t i o n mapping ( D C D M ) .
A p p l i c a t i o n s of these tools t o the nondestructive
assessment
of
lll-V
semiconductor
composition,
layer
thickness
and
defect
density
are
illustrated.
INTRODUCTION
W h i l e silicon, an elemental s e m i c o n d u c t o r
f r o m the f o u r t h c o l u m n of t h e periodic
table, is t h e building block of t o d a y ' s
electronics i n d u s t r y , s e m i c o n d u c t o r alloys
w i t h equal n u m b e r s of a t o m s f r o m t h e
third and f i f t h c o l u m n s are playing a small
but increasing role. Unlike silicon, these socalled l l l - V c o m p o u n d s e m i c o n d u c t o r s
readily
emit
light
under
electrical
s t i m u l a t i o n and so find use in a range of
optoelectronic
applications f r o m
high
e f f i c i e n c y solar cells t o the LED panel
lights f o u n d on m o s t pieces of high t e c h
gear t o the laser t h a t reads y o u r c o m p a c t
discs. T h e y also t y p i c a l l y have a higher
intrinsic resistance and a higher e l e c t r o n
v e l o c i t y t h a n silicon and so are f a v o u r e d
for t h e high f r e q u e n c y analog and high
speed digital electronics in s u c h i t e m s as
satellite
broadcast
receivers,
cellular
phones
and
supercomputers.
Device
designers tailor the properties of the
semiconductor
compound
for
each
application by using more t h a n one g r o u p
III or g r o u p V element in carefully
c o n t r o l l e d ratios, w h i l e maintaining the
overall s t o i c h i o m e t r y . T o take advantage
of the a l l o y ' s unique properties, it is
f r e q u e n t l y necessary t o use a series of t h i n
layers of d i f f e r e n t c o m p o s i t i o n g r o w n on
t o p of a single c r y s t a l substrate. The
thinnest of these layers can be o n l y a small
number of a t o m i c layers t h i c k . This article
describes s o m e of t h e challenges inherent
in using lll-V c o m p o u n d s e m i c o n d u c t o r s in
d e v i c e f a b r i c a t i o n and s o m e of the
m e t h o d s t h a t have been developed t o
m o n i t o r and help c o n t r o l their properties.
Consider the set of q u a t e r n a r y lll-V alloys:
ln x Ga, „As v P, v . These alloys are essential
t o t o d a y ' s fiber optic t e l e c o m m u n i c a t i o n s
systems,
being
used t o
make
the
necessary lasers, d e t e c t o r s and high speed
signal processing circuits. By changing the
ratio of indium t o gallium and arsenic t o
phosphorous, an alloy can be selected w i t h
a specific c o m b i n a t i o n of properties. The
first challenge is t o get t h e right ratios. If
t h e s y s t e m s design calls for a laser t h a t
e m i t s at
1 5 5 7 ± 5 n m , one of
the
preferred w a v e l e n g t h s for silica based fiber
optics, the
c o m p o s i t i o n of t h e light
e m i t t i n g a c t i v e layer, as described by t h e
indium and arsenic mole f r a c t i o n s , x and y ,
m u s t controlled t o w i t h i n ±
0.003.
U n f o r t u n a t e l y , m o s t of the traditional
90
Physics in Canada
M arch/Aprill 9 9 6
assay t o o l s , s u c h as energy dispersive xray analysis, have a c c u r a c y q u o t e d t o the
nearest 0 . 0 0 5 . Even the m o s t accurate
m e t h o d s have d i f f i c u l t y w i t h the small
sampling v o l u m e s (spot size a f e w
millimeter in d i a m e t e r , layers less t h a n 5
m i c r o m e t e r s thick). Therefore, k n o w l e d g e
of the absolute c o m p o s i t i o n is g i v e n up in
f a v o u r of more precise relative c o m p o s i t i o n
indicators. For t h i s quaternary alloy, a
c o n v e n i e n t c o m p r o m i s e is t o measure the
bandgap energy and the lattice c o n s t a n t of
the
material,
which
both
vary
in
predictable w a y s w i t h x and y . Only one
composition
will
have
a
specific
c o m b i n a t i o n of b o t h bandgap energy and
lattice c o n s t a n t .
The bandgap energy is the separation
b e t w e e n the highest ground state and the
l o w e s t excited state of the valence
electrons in the s e m i c o n d u c t o r . S t i m u l a t e d
d e - e x c i t a t i o n of electrons across the
bandgap creates the lasing photons the
d e v i c e designer is aiming f o r . Since the
bandgap
energy
defines
the
laser
w a v e l e n g t h and similar properties critical
t o other devices, k n o w l e d g e of the
bandgap
is
more
important
to
o p t o e l e c t r o n i c s design t h a n k n o w l e d g e of
the c o m p o s i t i o n w h i c h controls it. Luckily,
bandgap energy is m u c h easier t o measure
precisely
using the optical
methods
described in the f o l l o w i n g sections.
In an analogous fashion, the lattice
c o n s t a n t is also a more critical property for
optoelectronic
applications
than
the
c o m p o s i t i o n it depends upon. The lattice
constant
is the
fundamental
repeat
d i s t a n c e of the c r y s t a l lattice, t y p i c a l l y 0 . 5
t o 0 . 6 n m . In the first s t e p in the
fabrication
of
a
working
device,
s e m i c o n d u c t o r s layers are g r o w n on a
single c r y s t a l substrate epitaxially, i.e. in
such a w a y t h a t the a t o m s in the layers
line up w i t h those in the substrate. If the
lattice constant of the alloy is intrinsically
larger or smaller t h a n that of the substrate,
t h e n the c r y s t a l m u s t d i s t o r t tetragonally in
order t o m a t c h up in the plane of the
g r o w t h interface. The d i s t o r t i o n builds in
strain. If the strain becomes t o o high,
d i s l o c a t i o n s and other c r y s t a l d e f e c t s are
f o r m e d w h i c h u l t i m a t e l y degrade device
p e r f o r m a n c e . Some of the more advanced
designs deliberately build in small a m o u n t s
of strain t o m o d i f y the electronic band
s t r u c t u r e of the material in advantageous
w a y s . The thickness of the strained
material m u s t be kept l o w so that the t o t a l
strain energy is insufficient t o induce
d e f e c t f o r m a t i o n . For high performance
devices w i t h g o o d reliability it is necessary
t o c o n t r o l the relaxed lattice c o n s t a n t of
the layer relative t o t h a t of the substrate to
better t h a n one part in 10 3 . The x-ray
d i f f r a c t i o n m e t h o d s that are described in
this article are used t o detect m i n u t e
d i f f e r e n c e s b e t w e e n the lattice c o n s t a n t of
the epitaxial layer and the s u b s t r a t e .
The second challenge inherent in using
lll-V c o m p o u n d s e m i c o n d u c t o r s in device
f a b r i c a t i o n is t o get the layer thicknesses
right. For example, t h e m u l t i p l i c a t i o n layer
of
an avalanche photodiode is several
microns t h i c k . T o c o n t r o l the b r e a k d o w n
voltage of such a d e v i c e the thickness of
this layer m u s t be k n o w n t o better t h a n
2 % . The w a v e g u i d e layers of a laser are
more d i f f i c u l t still, in t h a t t h e y are only a
couple of hundred nanometers t h i c k . The
relative thickness tolerances are the same,
plus the index of refraction m u s t also be
t i g h t l y controlled. The e x t r e m e case occurs
in those devices w h e r e the active layer is
a series of q u a n t u m w e l l s , each o n l y a
handful of a t o m i c layers t h i c k . W h i l e
thickness control is made s o m e w h a t easier
since q u a n t u m w e l l s o n l y c o m e in integer
number of a t o m i c layers (monolayers)
t h i c k , measuring the t h i c k n e s s of these
t h i n layers requires i n n o v a t i v e solutions.
Optical m e t h o d s have been developed that
fill m o s t of these needs.
The third major property that needs t o be
measured and controlled for s u c c e s s f u l
device f a b r i c a t i o n is c o n c e n t r a t i o n of the
impurities added deliberately t o change the
conductivity
of
the
layers.
The
concentrations of these d o p a n t s that make
the d i f f e r e n c e b e t w e e n acceptable and
unusable material can be on the order of
1 0 ' 6 c m 3 or a ppb. A t present, f e w nond e s t r u c t i v e m e t h o d s exist for measuring
the dopant c o n c e n t r a t i o n q u a n t i t a t i v e l y ,
particularly in c o m p l e x d e v i c e s t r u c t u r e s .
Those that partially fill the need are beyond
the scope of this r e v i e w 1 .
The final i t e m t o be f o u n d on the list of
critical properties for o p t o e l e c t r o n i c device
m a n u f a c t u r e is d e f e c t d e n s i t y . D e f e c t s , at
the m o s t basic level, are misplaced a t o m s :
departures f r o m the e x p e c t e d translation
symmetry
of
the
lattice
or
the
incorporation of an unintended i m p u r i t y
a t o m . The more serious c r y s t a l d e f e c t s
m u s t be avoided because they make the
w a f e r more likely t o break during handling.
T h e y can be d e t e c t e d by x-ray d i f f r a c t i o n
methods as described later. Both c r y s t a l
d e f e c t s and impurities are important
because t h e y are o f t e n associated w i t h
electronic
states
which
change
the
c o n c e n t r a t i o n of free carriers and t h e r e b y
alter the operating characteristics of the
device.
Techniques
that
probe
the
r e c o m b i n a t i o n of injected carriers are very
e f f e c t i v e m o n i t o r s of the electrically active
d e f e c t d e n s i t y as w i l l be s h o w n .
Over the past seven years, a number of
scanning techniques have been developed
in the A d v a n c e d T e c h n o l o g y Laboratory at
Bell N o r t h e r n Research t o meet the
demand
for
rapid,
non-destructive
assessment of the substrates and epitaxial
layers used in the optoelectronic and high
speed electronic d e v i c e m a n u f a c t u r i n g of
its parent c o m p a n y , Nortel. Three of the
techniques w i l l be discussed: scanning
reflectance s p e c t r o s c o p y (sRS), scanning
photo-luminescence
(sPL) and
double
c r y s t a l x-ray d i f f r a c t i o n mapping ( D C D M ) .
The m e a s u r e m e n t s are c u r r e n t l y being
p e r f o r m e d by i n s t r u m e n t s designed and
built for us by W a t e r l o o
W a t e r l o o , Ontario.
Scientific,
of
T H I C K N E S S B Y S C A N N I N G REFLECTANCE
SPECTROSCOPY:
Scanning reflectance s p e c t r o s c o p y 2 makes
use of o p t i c a l interference t o infer the
t h i c k n e s s of an epitaxial layer and m a p its
d i s t r i b u t i o n across the w a f e r . In sRS, the
relative i n t e n s i t y of infrared light reflected
at normal incidence f r o m the sample is
measured as a f u n c t i o n of w a v e l e n g t h and
position. If the index of r e f r a c t i o n of the
t o p layer is s u f f i c i e n t l y d i f f e r e n t f r o m that
of the material beneath it, t h e n the t o t a l
reflected
light
will
be m o d i f i e d
by
c o n s t r u c t i v e and d e s t r u c t i v e interference
b e t w e e n light reflected at the t o p and
bottom
surfaces
of
the
layer.
The
reflectance s p e c t r u m for a 3 . 0 fjm thick
layer of InP g r o w n on a marker layer of
l n ; , 3 G a 4 , A s is s h o w n in Figure 1. The
a m p l i t u d e of the m o d u l a t i o n is d e t e r m i n e d
by the d i f f e r e n c e in the indices of
r e f r a c t i o n of the layer and the material
b e l o w it; in this e x a m p l e the d i f f e r e n c e is
0 . 3 6 ( ~ 10%). The spacing of the extrema is
related t o the product of t h e t h i c k n e s s and
index of r e f r a c t i o n of the t o p layer. Thinner
layers have m o r e w i d e l y spaced e x t r e m a .
Since the indices of r e f r a c t i o n of the
ln,Ga, „As v P, y alloys are k n o w n t o better
t h a n 1 part in 3 0 0 and the e x t r e m a
positions can be d e t e r m i n e d f r o m s u c h a
s p e c t r u m t o an a c c u r a c y of 1 part in
1 0 0 0 , the t h i c k n e s s of the layer can be
readily d e t e r m i n e d w i t h an overall a c c u r a c y
of better t h a n 0 . 3 % .
1300
Wavelength
Fig. 1
1500
The spectra tell us the thickness of the
layers at f i x e d points. To m a p the
thickness variation by taking spectra at
m a n y points on the w a f e r is t i m e
c o n s u m i n g and, luckily, unnecessary. If the
m o n i t o r i n g w a v e l e n g t h is f i x e d and the
w a f e r scanned under the beam, t h e n any
v a r i a t i o n in the product of index and
t h i c k n e s s w i l l appear as a change in
reflectance.
A n e x a m p l e of such a
reflectance m a p is s h o w n in Figure 2a.
Since the change in index of refraction
across t h e w a f e r due t o variation in
c o m p o s i t i o n or other f a c t o r s is usually a
hundred t i m e s or more smaller t h a n the
variation in epitaxial layer t h i c k n e s s ,
c o n t o u r s of equal reflectance correspond
very
well
to
lines of
equal
layer
thicknesses. To c o n v e r t the reflectance
m a p into a t h i c k n e s s map, it is necessary
t o i d e n t i f y the t h i c k n e s s associated w i t h
each c o n t o u r . The problem is not quite as
daunting as it m a y seem. If one calculates
the t h i c k n e s s of the layer for one point on
each adjacent e x t r e m a on the map, it is
possible t o a c c u r a t e l y interpolate the
t h i c k n e s s e s for the c o n t o u r s b e t w e e n
t h e m . Figure 2 b s h o w s the resultant
inferred thickness map. The pattern seen in
Figure 2 is a result of gas f l o w patterns in
the metal organic c h e m i c a l
vapour
d e p o s i t i o n ( M O C V D ) s y s t e m used t o
deposit the layers. There are 4 1 , 0 0 0 valid
data points on this map. Data acquisition
and analysis t o o k only 4 5 minutes. V e r y
f e w other analytical m e t h o d s provide this
speed, resolution and accuracy
nondestructive^.
BANDGAP ENERGY A N D DEFECT MAPPING
BY S C A N N I N G PHOTOLUMINESCENCE
A convenient m e t h o d for measuring the
bandgap energy of a s e m i c o n d u c t o r is
photoluminescence spectroscopy6.
In
p h o t o l u m i n e s c e n c e , a l o w p o w e r laser is
used to excite a ground state e l e c t r o n into
the band of e x c i t e d states. The e l e c t r o n
rapidly loses energy t o lattice v i b r a t i o n s
until it reaches the l o w e s t u n o c c u p i e d
excited state. It then drops back t o the
u p p e r m o s t e m p t y level in the band of
g r o u n d s t a t e s , g i v i n g up the excess energy
in the f o r m of a p h o t o n w i t h energy
roughly equal t o the bandgap energy. The
d i f f e r e n c e b e t w e e n the energy of the
e m i t t e d p h o t o n and the true bandgap is
very nearly kT, being s i m p l y related to h o w
m a n y of the states are already occupied by
t h e r m a l l y excited carriers. The spectra at
room t e m p e r a t u r e are broad in c o m p a r i s o n
t o those familiar t o atomic fluorescence
spectroscopists,
but
are
more
than
adequate t o a l l o w detailed maps of
bandgap v a r i a t i o n to be c o n s t r u c t e d .
Figure 3 is a scanning p h o t o l u m i n e s c e n c e
map of the bandgap energy d i s t r i b u t i o n for
a ln x Ga, „As v P, y layer g r o w n on InP. The
7 , 0 0 0 point m a p t o o k 16 hours t o acquire.
The t o t a l range of the data is 4 0 m e V ,
corresponding t o a standard d e v i a t i o n in
peak w a v e l e n g t h of 9 n m for the central
9 0 % of the w a f e r . For a laser w i t h a
w a v e l e n g t h tolerance only 10 n m w i d e ,
this implies that only a m a x i m u m of 4 5 %
of the d e v i c e s made f r o m this w a f e r w i l l
be w i t h i n specification. N o t i c e that the
p a t t e r n in Figure 3 is reminiscent t o the
t h i c k n e s s d i s t r i b u t i o n seen in Figure 2. The
gas v o r t i c e s in the M O C V D c h a m b e r t h a t
lead t o enhanced g r o w t h rate in t h e kidney
shaped central
region also lead
to
c o m p o s i t i o n variation and thus bandgap
energy s h i f t s . This is c o n f i r m e d w h e n the
sPL data is analyzed in c o n j u n c t i o n w i t h
the x-ray d i f f r a c t i o n data discussed in a
later section.
1700
(nm)
Normalized reflectance plotted as a
f u n c t i o n of wavelength for a 3 fjm
thick layer of InP on a 3.5 fjm thick
layer of In b3 Ga 4 7 As. The reflected light
spectrum of a bare InP substrate is
used t o normalize the data and thereby
reduce system artifacts.
The thinnest layer t h a t can be practically
measured by reflectance s p e c t r o s c o p y has
only one c o m p l e t e period in the spectral
range c o v e r e d by a single light source d e t e c t o r pair. For the range s h o w n in
Figure 1, w h i c h corresponds t o an InGaAs
d e t e c t o r and a t u n g s t e n lamp, the thinnest
measurable InP layer is ~ 3 0 0 nm t h i c k . For
thinner layers, m e a s u r e m e n t s based on the
polarization dependence of r e f l e c t i o n , s u c h
as e l l i p s o m e t r y 3 , are more appropriate.
Multi-layer s t r u c t u r e s have more c o m p l e x
spectra, w h i c h may be t h o u g h t of as the
superposition of the reflectance spectra of
each individual layer. They can be analyzed
by iterative f i t t i n g t o theoretical curves or
by using a m o d i f i e d Fourier approach 4 .
Fig. 2a The reflectance at a wavelength of
1 0 0 0 nm is displayed for an InP layer
g r o w n on an l n 5 3 G a 4 / A s marker layer.
The red and blue fringes correspond t o
thicknesses of InP w i t h reflectance
extrema at the map wavelength. The
InP substrate diameter is 5 0 mm.
Fig. 3:
Fig. b:
W i t h the additional information inferred
f r o m at least one reflectance spectrum
for each fringe, the sRS map can be
translated t o this thickness map. The
characteristic pattern is due t o the f l o w
of reactants in the deposition chamber
w h i c h enter at the top of this image.
The
peak
energy
of
the
photoluminescence emission is mapped
for a In.Ga, ,As y P, , layer deposited by
MOCVD. As in Figure 2, the gas f l o w
direction is top t o b o t t o m . The InP
wafer diameter is 5 0 m m .
A novel application of bandgap energy
mapping by sPL a l l o w s the m e a s u r e m e n t
of the t h i c k n e s s of q u a n t u m w e l l s 6 . One of
the m o s t d r a m a t i c e f f e c t of reducing the
t h i c k n e s s of an epitaxial layer t o b e l o w the
q u a n t u m limit ( 2 0 - 3 0 nm) is a rapid
increase in bandgap energy. A s can be
shown
with
simple
particle-in-a-box
models, w h i c h are surprisingly
good
91
a p p r o x i m a t i o n s t o the observed data, the
increase is inversely proportional t o t h e
w e l l t h i c k n e s s squared. Therefore if the
c o m p o s i t i o n of t h e w e l l d o e s n ' t v a r y , maps
of q u a n t u m w e l l sPL energy can be d i r e c t l y
interpreted in t e r m s of variations in w e l l
t h i c k n e s s . W h e n ternary or quaternary
alloys are used as the w e l l material, sPL
energy data can still be used t o m a p the
w e l l t h i c k n e s s as long as the s t r u c t u r e
includes a reference layer of t h e same
nominal c o m p o s i t i o n and of a t h i c k n e s s in
excess of the q u a n t u m
limit. T h e n the
energy s h i f t s due t o c o m p o s i t i o n v a r i a t i o n
( w h i c h s h o w up in b o t h maps) can be
separated f r o m those due t o g r o w t h rate
v a r i a t i o n ( w h i c h o n l y s h o w up in the
q u a n t u m w e l l map). A n example of a
nominally 1 4 m o n o l a y e r ( 8 . 2 nm) t h i c k
ln63Gaa7As quantum well grown
by
M O C V D is s h o w n in Figure 4. Clearly
defined regions appear w i t h d i s t i n c t energy
s h i f t s . The assignment of the bands t o a
specific number of m o n o l a y e r s is made on
the basis of c o m p a r i s o n t o t h e o r y or a one
t i m e c a l i b r a t i o n w i t h a d e s t r u c t i v e analysis
m e t h o d s u c h as t r a n s m i s s i o n e l e c t r o n
microscopy. The quantum well thickness
p a t t e r n is similar t o t h a t f o u n d by sRS for
t h i c k e r layers.
had not been properly cleaned f r o m the
w a f e r prior t o epitaxial layer g r o w t h . It is
not u n c o m m o n t o find w i t h sPL that
c o n t a m i n a t i o n spreads many millimeters
a w a y f r o m its point of origin. Other
sources of epitaxial layer d e f e c t s have
been f o u n d by this sensitive m e t h o d ,
including: substrate d e f e c t s , residues of
cleaning chemicals and impurities in the
gases used for g r o w t h . In m a n y instances,
t h e c o n c e n t r a t i o n of the impurities w h i c h
have a d r a m a t i c e f f e c t on sPL intensity and
aspects of device performance 7 w a s f o u n d
t o be at or b e l o w the d e t e c t i o n limit of
traditional i m p u r i t y analysis m e t h o d s (i.e.
below 1 0 ' 6 c m 3 ) .
Fig. 5
The photoluminescence intensity at a
fixed wavelength is mapped for a
M O C V D g r o w n ln x Ga, .As,?, y layer. The
sPL intensity is strongly reduced in the
vicinity of particulates w h i c h were
inadvertently
introduced
prior
to
g r o w t h . The InP wafer diameter is
50 mm.
DEFECT
AND
LATTICE
CONSTANT
MAPPING BY DOUBLE CRYSTAL X - R A Y
DIFFRACTION
Fig. 4
The q u a n t u m energy shift is mapped
by
subtracting
the
observed
photoluminescence peak energy of a
In s3 Ga 4,As q u a n t u m well f r o m that of
a thick l n 6 3 G a 4 / A s reference layer
g r o w n beneath it. Each band of
distinct energy is assigned t o a specific
number of monolayers based on a
separate calibration. The layers were
g r o w n by M O C V D on a 7 6 m m
diameter InP wafer .
The
intensity
of
the
emitted
p h o t o l u m i n e s c e n c e is a f u n c t i o n of the
e x c i t a t i o n rate and the rate at w h i c h the
electron d e - e x c i t e t h r o u g h
alternative
paths t h a t do not involve the e m i s s i o n of a
near bandgap p h o t o n . Surface states or
mid-bandgap d e f e c t states f r e q u e n t l y act
as non-radiative d e - e x c i t a t i o n paths. If the
e x c i t a t i o n p o w e r is not so high t h a t the
d e n s i t y of p h o t o - e x c i t e d electrons exceeds
the d e n s i t y of non-radiative centers, t h a n
any decrease in sPL intensity is d i r e c t l y
related t o the d e n s i t y of d e f e c t s . Figure 5
s h o w s an i n t e r e s t i n g e x a m p l e of a sPL
intensity
map
measured
under
low
e x c i t a t i o n c o n d i t i o n s . The w a v e l e n g t h w a s
f i x e d t o be near the peak of t h e sPL
s p e c t r u m and t h e w a f e r w a s stepped
2 0 0 /Jm on center t o build u p a high spatial
resolution map. The 4 8 , 0 0 0 point m a p
t o o k 35 m i n u t e s t o acquire. A t t h e cores
of the c o n s p i c u o u s l o w sPL intensity
regions w e r e t i n y specks of d u s t w h i c h
92
Physics in Canada M a r c h / A p r i l l 9 9 6
The c r y s t a l p e r f e c t i o n of the sample is
m o s t easily assessed by x - r a y d i f f r a c t i o n .
If t h e i n t e r a t o m i c plane spacing, the
w a v e l e n g t h of the x-rays and the angle of
incidence w i t h respect t o the c r y s t a l
planes s a t i s f y the w e l l k n o w n Bragg
d i f f r a c t i o n condition, the x - r a y s d i f f r a c t
s t r o n g l y f r o m a single c r y s t a l sample. If
there is any local d e v i a t i o n in t h e sample
c r y s t a l plane orientation or spacing, the
d i f f r a c t i o n c o n d i t i o n w i l l not be satisfied
and the detected x-ray intensity falls.
Double c r y s t a l d i f f r a c t i o n 8 is a variant of
the classical m e t h o d in w h i c h d i f f r a c t i o n
f r o m a first c r y s t a l is used t o reduce the
divergence of the x-ray beam before it is
d i f f r a c t e d f r o m the t e s t w a f e r . The
m e a s u r e m e n t consists of m o n i t o r i n g the
d i f f r a c t e d x-ray intensity as the sample is
rocked t h r o u g h the o p t i m a l angle. The
peak angle, intensity and the full w i d t h half
m a x i m u m of the rocking c u r v e are
recorded. A l t h o u g h t h e actual
angle
corresponding t o the peak intensity has
limited meaning due t o u n c e r t a i n t y in the
i n s t r u m e n t ' s true zero position, relative
angle changes can be mapped w i t h arc
second precision and are used t o q u a n t i f y
long range lattice c u r v a t u r e and the
angular d e v i a t i o n across l o w angle grain
boundaries9.
This
method
is
c o m p l e m e n t a r y t o the higher
spatial
resolution t o p o g r a p h y m e t h o d s w h e r e the
w a f e r is imaged for a f i x e d rock angle 1 0 .
In Figure 6 the peak full w i d t h at half
m a x i m u m ( f w h m ) map of an average
quality 7 6 m m diameter GaAs substrate is
displayed. It w a s obtained by measuring
rocking curves in a m a t r i x of x - y points on
a 7 5 0 ^/m grid over a 8 hour period. There
are
many
high
fwhm
features,
p r e d o m i n a n t l y at the w a f e r periphery, but
also running diagonally across the w a f e r .
From the peak angle maps acquired at the
same t i m e , one c a n i d e n t i f y
these
elongated features as l o w angle grain
boundaries w h e r e the lattice planes tilt by
10 t o 3 0 " w i t h respect t o one another. A t
those positions the rocking curves broaden
or even split since the x-ray beam
straddles
the
boundary.
When
the
m i s o r i e n t a t i o n across these features is
v e r y large ( > 5 0 " ) , the mechanical s t r e n g t h
of the w a f e r is c o m p r o m i s e d . Batches of
substrates can be screened this w a y t o
eliminate those m o s t likely t o break.
Fig. 6
The DCD f w h m is mapped for a
commercial grade semi insulating GaAs
wafer g r o w n by liquid encapsulated
Czochralski. The regions of higher than
normal f w h m correspond t o low angle
grain boundaries or other
crystal
defects. The wafer diameter is 7 6 mm.
D C D M is an i m p o r t a n t t o o l f o r t h e
evaluation of epitaxial layers. W h e n there
are t w o d i f f e r e n t c r y s t a l plane spacings
w i t h i n t h e x-ray sampling v o l u m e (e.g. a
not t o o t h i c k , slightly m i s m a t c h e d layer o n
a substrate), the d i f f r a c t i o n c o n d i t i o n is
satisfied at t w o d i f f e r e n t angles. The DCD
rocking c u r v e t h e n s h o w s t w o d i s t i n c t
peaks, w h o s e separation is linearly related
t o lattice strain. Device engineers can
examine D C D M peak separation maps and
decide w h e t h e r the strain is w i t h i n
acceptable
tolerances.
Alternatively,
D C D M peak separation maps can be used
t o d e t e r m i n e ternary alloy c o m p o s i t i o n .
The peak separation observed for an
AI„Ga, x A s layer g r o w n by molecular beam
e p i t a x y (MBE) on GaAs is s h o w n in Figure
7. The u n i f o r m i t y is quite good: the
inferred c o m p o s i t i o n is x = . 3 0 4 ± . 0 0 5 .
H o w e v e r the DCD m a p s h o w s an edge-tocenter variation that goes counter t o
e x p e c t a t i o n s based u p o n flux d i s t r i b u t i o n s
observed in the g r o w t h c h a m b e r . The
central portion of the w a f e r has a higher
than
expected
peak
separation,
corresponding t o ~ 1 % more aluminum in the
alloy. The root cause w a s traced d o w n t o
interactions w i t h the substrate holder in
t h e g r o w t h chamber. Due t o the placement
of the substrate heater and the high
t h e r m a l c o n d u c t i v i t y of the holder, the
holder is generally cooler t h a n the w a f e r .
Depending on t h e degree of t h e r m a l
c o n t a c t b e t w e e n the w a f e r and the holder,
t h e center of t h e w a f e r c a n be up t o 15°C
h o t t e r t h a n t h e edge. U n f o r t u n a t e l y , at the
t e m p e r a t u r e s p r e f e r r e d for the g r o w t h of
high q u a l i t y AI„Ga, „ A s , a s i g n i f i c a n t
p r o p o r t i o n of the g a l l i u m a t o m s s t r i k i n g t h e
w a f e r s u r f a c e re-evaporate. In the hot
central zone e v e n m o r e g a l l i u m e v a p o r a t e s ,
locally e n h a n c i n g the
aluminum mole
f r a c t i o n . By redesigning the holder, this
e f f e c t can be m i n i m i z e d .
w h i c h has led t o m a n y
unexpected
discoveries
about
sources
of
nonr e p r o d u c i b i l i t y and n o n - u n i f o r m i t y . W i t h o u t
the i n s i g h t s that sRS, sPL and D C D M have
p r o v i d e d , the j o b of d e v e l o p i n g a d v a n c e d
o p t o e l e c t r o n i c s w o u l d have been m u c h
more difficult.
REFERENCES
1.
For example: C.J. Miner, Semiconductor
Characterization:
Present Status
and
Future Challenges,
ed. W . M . Bullis,
D.G. Seiler and A.C. Diebold (AIP,
Woodbury, N.Y., 1995) 6 0 5 , and other
papers in the same volume.
L.E. T a r o f , C . J . Miner and C. B l a a u w ,
J. A p p l . Phys., 6 8 ( 1 9 9 0 ) 2 9 2 7 .
Fig. 7
The DCD peak separation is displayed
for a AI 3 Ga , A s layer g r o w n by MBE o n
GaAs. The central area o f larger
absolute peak separation w a s caused
by enhanced gallium desorption during
g r o w t h at a local h o t spot. The wafer
diameter is 7 6 m m .
For q u a t e r n a r y alloys, sPL peak e n e r g y
data and D C D M m u s t be c o m b i n e d t o infer
b o t h the g r o u p III and g r o u p V m o l e
f r a c t i o n s . W i t h t h i s d a t a , f o r i n s t a n c e , it is
possible t o s h o w t h a t the d o w n w a r d
e n e r g y s h i f t s h o w n in Figure 3 and the
e n h a n c e d q u a n t u m w e l l g r o w t h rate s h o w n
in Figure 4 are the c o n s e q u e n c e of
enhanced
arsenic
incorporation
(y
increases by 0 . 0 1 5). The ratio of i n d i u m t o
g a l l i u m in t h e ln x Ga, „As v P,. v layers is
largely u n c h a n g e d across t h e
wafer.
M o d i f i c a t i o n s t o the g r o w t h c h a m b e r
g e o m e t r y and t h e use of s u b s t r a t e r o t a t i o n
reduce the n o n - u n i f o r m i t y by a f a c t o r of 2.
In t h i s w a y , t h e t i g h t s p e c i f i c a t i o n s o n
laser w a v e l e n g t h and l a t t i c e s t r a i n i m p o s e d
by the a p p l i c a t i o n c a n be m e t .
3.
4.
P.L. Swart and B.M. Lacquet, J.
Phys., 7 0 (1991) 1 0 6 9 .
5.
C.J. Miner, Semicond.
(1992) A 1 0 .
6.
N. Puetz, G. H illier, C.J. Miner and
A . J . Spring Thorpe, Crystal
Properties
and Preparations, 3 2 - 3 4 (1991) 5 1 4 .
Sci.
Appt.
Tech.,
I.C. Bassignana,
N. Puetz, J. Appl.
4299.
est disponible
sur microfilm ou
microfiche
Les volumes antérieurs de
cette publication sont
également disponibles
sur microfilm ou
michrofiche.
7
C.J. Miner, D.G. Knight, B. Watt,
C. Blaauw and N. Puetz, IEEE LEOS'90
Conference Proceedings (1990) 6 1 5 .
SUMMARY
The t e c h n i q u e s d e s c r i b e d here h a v e p r o v e n
t o be essential t o the d e v e l o p m e n t of the
l l l - V c o m p o u n d s e m i c o n d u c t o r s for a
v a r i e t y of o p t o e l e c t r o n i c a p p l i c a t i o n s . T h e y
h a v e d e m o n s t r a t e d the required a c c u r a c y
and p r e c i s i o n t p m o n i t o r several of t h e key
p r o p e r t i e s . T h e y provide rapid f e e d b a c k , so
t h a t it is possible t o q u i c k l y adjust g r o w t h
c o n d i t i o n s t o hit t i g h t s p e c i f i c a t i o n s . T h e y
are a d e f i n i t e
improvement
on
the
traditional
approaches
of
growing
c a l i b r a t i o n w a f e r s for d e s t r u c t i v e analysis
of a small n u m b e r of selected p o i n t s , or
w a i t i n g u n t i l t h e d e v i c e s are f a b r i c a t e d and
t e s t e d ( t y p i c a l l y 3 - 6 w e e k s ) . These n e w
t e c h n i q u e s have been o p t i m i z e d f o r speed,
t o m a k e high spatial r e s o l u t i o n m a p p i n g
p r a c t i c a l . By s t u d y i n g the p a t t e r n of t h e
properties m e a s u r e d o n t h e w a f e r , it is
f r e q u e n t l y o b v i o u s w h y t h e v a r i a t i o n s have
o c c u r r e d and w h a t m e a s u r e s s h o u l d be
t a k e n t o c o r r e c t t h e m . Because these t e s t s
are
non-destructive,
there
is
little
reluctance o n t h e part of m a n u f a c t u r i n g
engineers t o m o n i t o r f r e q u e n t l y , a practice
H. Tompkins, A User's
Guide
to
Ellipsometry, Academic Press, 1 9 9 3 .
Cette
Revue
C.J.
Miner
and
Phys., 65 (1989)
C.J. Miner, Proc. Semi-Insulating
lll-V
Materials Conference, Warsaw, Poland,
ed. M.Godlewski (World
Scientific
Press, Singapore, 1994) 8 7 .
Pour de plus amples
renseignements, i •euillez
communiquer avec :
ift
Micromedia
Limited
Canada 's Information
People
10.
11.
I.C. Bassignana and D.A. Macquistan, Proc.
Semi-Insulating lll-V Materials Conference,
Ixtapa, Mexico, ed. C J . Miner, W. Ford and
E.R. Weber (I0P Publishng, Bristol. 1993)
183.
20 l'ictoria Street.
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1-800-387-2689
C.J. Miner, B. W a t t , W . T . Moore,
A . Majeed and A . J . Spring Thorpe,
J. Vac. Sci. Tech., B11 (1993) 9 9 8 .
93
T H E E A R L Y H I S T O R Y O F W O M E N IN U N I V E R S I T Y P H Y S I C S : A T O R O N T O C A S E S T U D Y
by
A l i s o n Prentice
Professor of H i s t o r y , O n t a r i o Institute for Studies in Education
One o f t e n f i n d s , in discussions of w o m e n
in t h e sciences, references t o w o m e n ' s
presence in " n o n - t r a d i t i o n a l " areas of
s t u d y . The i m p l i c a t i o n is usually t h a t
" t r a d i t i o n a l l y " w o m e n w e r e not t o be
f o u n d in the sciences generally, or in
particular sciences s u c h as p h y s i c s . There
is little t r u t h in t h i s idea.
That w o m e n have studied all of the
sciences and have been i n v o l v e d in
scientific
work
in all disciplines
is
increasingly d e m o n s t r a t e d by a g r o w i n g
literature. 1
In A u s t r a l i a ,
as
Marjorie
Theobald has s h o w n , science w a s part of
the " w o m e n ' s s t u d i e s " c u r r i c u l u m of
women's
schools
and
academies
t h r o u g h o u t the colonial period. A c o l l e c t i o n
of essays dealing c h i e f l y w i t h m o d e r n
Europe reveals w o m e n at w o r k in the
sciences, f r o m the e i g h t e e n t h c e n t u r y
w h e n m u c h science w a s c o n d u c t e d in
d o m e s t i c or s e m i - d o m e s t i c s e t t i n g s , t o
more recent t i m e s . A recent collection,
edited by Marianne G o s z t o n y i A i n l e y ,
carries t h e s t o r y t o Canada. W h i l e none of
these studies suggests t h a t it w a s easy for
w o m e n t o be s c i e n t i s t s , the overall
message of i n v o l v e m e n t is clear. W o m e n
have a l w a y s been interested in science and
studied it w h e n e v e r and w h e r e v e r t h e y
could manage t o do so; and some w o m e n ,
in e v e r y period since the e i g h t e e n t h
c e n t u r y , have reached the highest levels of
excellence in all areas of
scientific
endeavour. That science - even physics - is
a " n o n - t r a d i t i o n a l " area for w o m e n is
largely false.
H o w , then, did the idea develop? The s t o r y
of w o m e n in physics at t h e U n i v e r s i t y of
T o r o n t o is suggestive. W o m e n appear t o
have s t u d i e d p h y s i c s at T o r o n t o v e r y soon
after their a d m i s s i o n t o the u n i v e r s i t y in
1 8 8 4 . By the early decades of the
twentieth century, w o m e n were making
their mark in g r a d u a t e physics and earning
d o c t o r a t e s as w e l l as m a s t e r ' s degrees in
t h e field. In t h e 1 9 4 0 s , t h e D e p a r t m e n t of
Physics even a d m i t t e d several w o m e n into
t h e professorial ranks and, s h o r t l y after the
middle of t h e c e n t u r y , n a m e d its first
w o m a n full professor. The promise of the
first half of the c e n t u r y w a s not fulfilled,
h o w e v e r , in t h e s e c o n d half.
The s t o r y of Elizabeth Rebecca Laird
illustrates t h e early presence of w o m e n in
undergraduate physics at T o r o n t o . One of
t w o sisters w h o g r a v i t a t e d t o the s t u d y of
science (Annie Laird m o v e d f r o m c h e m i s t r y
t o household science and w a s the head of
T o r o n t o ' s household science d e p a r t m e n t
for 3 4 years) Elizabeth chose physics after
her m a t r i c u l a t i o n f r o m London Central
Collegiate and graduated f r o m T o r o n t o
w i t h honours in m a t h e m a t i c s and physics
in 1 8 9 6 . But the fact t h a t she "had s t o o d
first for three years running" in her class
did not w i n her the c o v e t e d f e l l o w s h i p t h a t
w o u l d have g i v e n her several years of
graduate s t u d y abroad; this scholarship
w a s designated, as t h e author of a
94
Physics in Canada
M arch/Aprill 9 9 6
n e w s p a p e r obituary later described it, for
a " h e " not a " s h e . " 2 Undaunted, Elizabeth
Laird took a teaching post at
the
prestigious Ontario Ladies College at
3
Whitby.
W i t h i n t w o years, a local
n e w s p a p e r w a s able t o report that " M i s s
Lizzie R. Laird" w a s s t u d y i n g physics at
B r y n M a w r College in Pennsylvania and
had been g r a n t e d a M a r y Garrett European
f e l l o w s h i p . This distinguished a w a r d , one
of only t w o handed out annually, entitled
its recipient t o a year of s t u d y in Europe.
Elizabeth's f e l l o w s h i p year must have been
especially r e w a r d i n g , for she w o r k e d w i t h
M a x Planck in Berlin, just prior t o his
publication of " t h e papers that launched
t h e q u a n t u m t h e o r y . " 4 A f t e r the granting
of her d o c t o r a t e in 1 9 0 1 , Elizabeth Laird
w o u l d teach physics at M o u n t Holyoke, a
small N e w England college for w o m e n ,
heading the d e p a r t m e n t there f r o m 1 9 0 3
until 1 9 4 0 . In that year she " r e t i r e d " to
more t h a n a decade of f u r t h e r w o r k , on a
volunteer basis, at the U n i v e r s i t y of
W e s t e r n Ontario, before her
second
retirement in 1953.^
That Elizabeth Laird w a s not alone as an
early w o m a n undergraduate in physics at
T o r o n t o w e k n o w f r o m the s t o r y of
Caroline Macdonald, a physics graduate
w h o u l t i m a t e l y made her career as a
missionary in Japan. M a c d o n a l d , the
second w o m a n t o graduate in honours
m a t h e m a t i c s and physics at T o r o n t o ,
earned her degree in 1 9 0 1 . Unlike Laird,
Macdonald
was
offered
a
graduate
f e l l o w s h i p . The e f f o r t s of J . C . McLennan
t o persuade her t o accept the a w a r d w e r e ,
h o w e v e r , unavailing. Perhaps, as Caroline
M a c d o n a l d ' s biographer suggests, she
f o r e s a w that the path of a w o m a n
physicist in Canada w o u l d be d i f f i c u l t , but
it is even more likely that "she w a s already
c o m m i t t e d in quite another d i r e c t i o n . "
A f t e r a period w o r k i n g for the V W C A , this
talented and d y n a m i c w o m a n m o v e d t o
J a p a n w h e r e she became involved in
s e t t l e m e n t w o r k and eventually in the
Japanese labour m o v e m e n t . 6
Nevertheless, w o m e n eventually d i d m o v e
into graduate s t u d y in physics at Toronto.
A n e x a m i n a t i o n of the u n i v e r s i t y calendars
and directories reveals t h e m , 7 as does
Elizabeth J . A l l i n ' s brief history of the
d e p a r t m e n t . Physics at the U n i v e r s i t y of
Toronto, 1843-1980." Vivian Ellsworth
Pound w a s the first w o m a n to earn a
d o c t o r a t e in physics at the u n i v e r s i t y ,
receiving her degree in 1 9 1 3 . Pound
lectured at Queen's f r o m 1 9 1 2 t o 1 9 1 7 ,
w h e n she evidently m o v e d briefly into the
w o r l d of business. But she returned t o
u n i v e r s i t y science in 1 9 2 2 w h e n she f o u n d
a position in m a t h e m a t i c s at Buffalo. Like
Elizabeth Laird, V i v i a n Pound may have
been f o r c e d t o leave Canada in order t o
pursue a career in u n i v e r s i t y teaching and
research. W e k n o w f r o m A m e r i c a n M e n of
Science |sic| ( 1 9 6 1 ) that she remained at
Buffalo and w a s p r o m o t e d t o full professor,
retiring as Professor Emeritus in 1 9 5 5 .
In short order, other w o m e n f o l l o w e d V i v i a n
Pound into d o c t o r a l studies in physics at
T o r o n t o . Their heyday c a m e in the 1 9 2 0 s
and early 3 0 s . B e t w e e n 1 9 2 6 and 1 9 3 3 , six
w o m e n w e r e a w a r d e d Ph.Ds in p h y s i c s :
M a t t i e Levi Rotenberg, Elizabeth Cohen,
Beatrice Reid Deacon, Elizabeth J . Allin,
Florence M . Quinlan, and M a y A n n e t t s
S m i t h . Indeed, b e t w e e n 1 9 0 0 , w h e n
J . C . McLennan w a s granted U. of T . ' s first
Ph.D in p h y s i c s , and 1 9 3 3 , w h e n f i v e
physics d o c t o r a t e s w e r e a w a r d e d , w o m e n
c o n s t i t u t e d nearly one quarter of the 31
w i n n e r s of this degree at T o r o n t o . This
percentage m a y have been considerably
higher t h a n the n o r m . A s published
statistics are by decade, rather t h a n
c u m u l a t i v e , c o m p a r i s o n s cannot be e x a c t .
But w e do k n o w t h a t , in 1 9 3 0 - 3 1 , w h e n
Canadian w o m e n ' s i n v o l v e m e n t i n g r a d u a t e
s t u d y appears t o have t e m p o r a r i l y peaked,
w o m e n earned slightly more t h a n o n e - f i f t h
of all m a s t e r ' s degrees g r a n t e d in all fields in
Canada, but only seven percent of the
d o c t o r a t e s . 9 For w o m e n to have been the
recipients of over 2 0 percent of T o r o n t o ' s
first 31 Ph.Ds in physics m u s t therefore be
c o u n t e d a singular a c h i e v e m e n t .
The success w a s shortlived. A f t e r 1 9 3 3
w o m e n disappear f r o m the lists of T o r o n t o
d o c t o r a t e s in physics, not t o reappear for
some time. Their disappearance cannot be
attributed entirely t o lack of m e n t o r s h i p , for
the d e p a r t m e n t , under J . C M c L e n n a n and
E.F. Burton, f o l l o w e d up its support of
w o m e n s t u d e n t s in physics w i t h t h e
granting of some teaching a p p o i n t m e n t s .
Even prior t o 1 9 2 0 - 2 1 , a t o t a l of 25 w o m e n
taught for the physics d e p a r t m e n t at
T o r o n t o , although most w e r e probably
m a s t e r ' s s t u d e n t s and f e w taught for more
than t w o or three years. One of these early
assistants in p h y s i c s , A n n i e Theresa Reed
(B.A. 1897) w a s an e x c e p t i o n t o the rule.
The calendars and directories list her as
"Class A s s i s t a n t in P h y s i c s " f r o m as early
as 1 9 1 1 and into the 1 9 3 0 s , but by 1 9 2 4 25 she also held the title " S e c r e t a r y t o the
Physics D e p a r t m e n t , " a role that she had
evidently played for some t i m e . Holding
onto the latter position until 1 9 4 6 , Annie
Reed became not just a f i x t u r e , but a force
in the d e p a r t m e n t , r e m e m b e r e d f o n d l y for
her humour as w e l l as her p o w e r . ' 0
T o w a r d s t h e end of W o r l d W a r I, several
w o m e n w e r e p r o m o t e d f r o m assistantships
t o positions as d e m o n s t r a t o r s . One of the
w o m e n w h o began teaching f o r the
d e p a r t m e n t at this t i m e (earning her
d o c t o r a t e over a decade later)
was
Florence Quinlan. Quinlan w a s t o carve out
a special niche for herself t e a c h i n g physics
t o household science and music s t u d e n t s
at the u n i v e r s i t y and, like Reed, had a long
career at T o r o n t o . Nor w a s she alone, for
she w a s soon joined in undergraduate
teaching by another T o r o n t o g r a d u a t e ,
Kathleen Crossley (B.A. 1 9 1 8 ) . Crossley
never obtained either a m a s t e r ' s degree or
the d o c t o r a t e , but nevertheless taught at
the u n i v e r s i t y for more t h a n three decades,
t o be " r e m e m b e r e d by m a n y g e n e r a t i o n s
of first year s t u d e n t s " as t h e i n s t r u c t o r
w h o i n t r o d u c e d t h e m to p h y s i c s . " The
third w o m a n w h o w o u l d spend her entire
career teaching physics at the U n i v e r s i t y
of T o r o n t o w a s Elizabeth Allin, w h o t a u g h t
in various capacities f r o m the m i d - 1 9 2 0 s ,
joining the staff as " D e m o n s t r a t o r and
Research A s s i s t a n t " in 1 9 3 1 , for a career
t h a t did not end until she retired in 1 9 7 2 .
Other w o m e n t a u g h t for the d e p a r t m e n t ,
but none so c o n t i n u o u s l y or for such long
periods as Quinlan, Crossley and A l l i n , all
of w h o m also received p r o m o t i o n s into the
professoriate in the early 1 9 4 0 s . The four
w o m e n w h o perhaps c a m e closest t o
having careers in physics at T o r o n t o w e r e
M a y A n n e t t s S m i t h , Beatrice Reid Deacon,
M a t t i e Levi Rotenberg and
Elizabeth
Cohen, all w o m e n w i t h T o r o n t o Ph.Ds
f r o m the i n t e r w a r years.
Continuing
with
her
research
and
demonstrating
work
after
her
1933
d o c t o r a t e , M a y A n n e t t s g a v e up any
chance for a position at T o r o n t o w h e n she
left for England t o be married in 1 9 3 6 . 1 2
The stories of the other three w o m e n are
more a m b i g u o u s . All three t a u g h t at
T o r o n t o for m a n y
years after
their
d o c t o r a t e s , but w e r e never p r o m o t e d
3
beyond the rank of i n s t r u c t o r . ' Beatrice
Deacon and M a t t i e Rotenberg m a y have
experienced d i s c r i m i n a t i o n because t h e y
w e r e married. During the first half of the
twentieth
century,
elementary
and
secondary w o m e n teachers t y p i c a l l y lost
their positions on marriage; m o s t w o m e n
on u n i v e r s i t y faculties w e r e also e x p e c t e d
- or asked - t o leave w h e n t h e y tied t h e
marital k n o t . Yet the U n i v e r s i t y of T o r o n t o
w a s not c o n s i s t e n t on this point. The
biologist N o r m a Ford and the a s t r o n o m e r
Helen Hogg w e r e a m o n g several w o m e n
scholars
who
managed
to
combine
marriage and t e a c h i n g at T o r o n t o during
this period, gaining
both
permanent
positions and p r o m o t i o n s . 1 4 Deacon and
Rotenberg, it w o u l d appear, w e r e not so
f o r t u n a t e . I have been able t o d i s c o v e r
next t o nothing about Beatrice Deacon,
except that she w a s a c t i v e in teaching and
research at T o r o n t o until at least 1 9 4 7 - 4 8
and w a s still a m e m b e r of the Canadian
A s s o c i a t i o n of Physicists in 1 9 5 2 . M a t t i e
Rotenberg w a s perhaps a special case, as
she eventually had m a n y other irons in the
fire. In addition t o her ongoing physics
teaching and her marriage, she gradually
m o v e d into broadcasting for the CBC and
became
deeply
involved
in
Jewish
e d u c a t i o n and p h i l a n t h r o p y . 1 6
It w o u l d be useful t o k n o w more about
Elizabeth Cohen, the one single w o m a n in
this g r o u p of four w o m e n p h y s i c i s t s w h o
seems m o s t likely to have w a n t e d or
needed a f u l l - t i m e career in science.
Cohen's
1929
Toronto doctorate
in
physics w a s r e w a r d e d by a year of s t u d y
in Britain (divided b e t w e e n the Universities
of
London
and
Bristol)
and
an
i n s t r u c t o r s h i p , f o l l o w e d by an assistant
professorship at M o u n t H o l y o k e during
Elizabeth Laird's last decade as head of
physics there. Financial problems f o r c e d a
r e d u c t i o n in staff at t h e N e w England
college, h o w e v e r , and Cohen returned t o
T o r o n t o in 1 9 3 5 . There she w o r k e d for the
d e p a r t m e n t in various capacities, but
w i t h o u t p r o m o t i o n , until the m i d - 1 9 5 0 s . 1 '
W h i l e I have d i s c o v e r e d no evidence of
a n t i - s e m i t i s m w o r k i n g against Elizabeth
Cohen or M a t t i e Rotenberg, it is not
inconceivable t h a t cultural and religious
d i f f e r e n c e played s o m e role in blocking
their a d v a n c e m e n t , especially in the case
of the unmarried Elizabeth Cohen. 1 8
A s w e have seen, a m o n g the w o m e n w h o
taught for the physics d e p a r t m e n t , only
Florence Quinlan, Kathleen Crossley, and
Elizabeth Allin made it into the professorial
ranks. Their p r o m o t i o n occurred in 1 9 4 1 4 2 , w h e n the exigencies of w a r m a y finally
have revealed the d e p a r t m e n t ' s reliance on
these w o m e n ' s w o r k . 1 9 A s Elizabeth A l l i n
later recalled, all three felt " v e r y l u c k y " t o
receive
appointments
as
assistant
professors - despite their several decades
of service in the cases of Quinlan and
Crossley, and the t e n years or more that
Allin herself
had t a u g h t
physics
at
T o r o n t o . 2 0 In f a c t , the late 1 9 3 0 s had been
t r y i n g years, especially for the w o m e n
p h y s i c i s t s . There w e r e eleven m e n in the
T o r o n t o physics professoriate at T o r o n t o
by 1 9 3 7 , but no w o m a n had yet joined
t h e m ; indeed the Great Depression w a s
used as an e x c u s e t o r e m o v e talented
married w o m e n f r o m the teaching ranks
altogether. 2 1 A n d d e p r e s s i o n w a s f o l l o w e d
by w a r . During the Second W o r l d W a r ,
several of T o r o n t o ' s male p h y s i c i s t s w e r e
seconded t o various g o v e r n m e n t and
m i l i t a r y jobs, leaving huge teaching loads
for those w h o w e r e left behind. Quinlan,
Crossley, and Allin did receive their
assistant professorships, but t h e y certainly
w o r k e d v e r y hard for t h e m . Elizabeth Allin,
for e x a m p l e , taught classes as large as f i v e
hundred s t u d e n t s , chiefly a r m e d forces
personnel w h o needed t o learn the
r u d i m e n t s of radar. 2 2
During the i m m e d i a t e p o s t - w a r years,
p h y s i c i s t s at T o r o n t o w e r e anxious to get
back t o the research t h a t had been laid
aside in 1 9 3 9 and very soon the graduate
program doubled in size. But, of the
w o m e n p h y s i c i s t s , only Elizabeth Allin
appears t o have been involved in graduate
teaching and research during this period.
Part of a t e a m that w o r k e d in the area of
s p e c t r o s c o p y , she delivered papers at
physics s o c i e t y m e e t i n g s and w a s a m o n g
t h o s e w h o w e r e i n s t r u m e n t a l in f o u n d i n g
the Canadian A s s o c i a t i o n of Professional
Physicists (later t h e Canadian A s s o c i a t i o n
of Physicists) in the late 1 9 4 0 s . A s she
recalled in i n t e r v i e w s in 1 9 9 1 and 1 9 9 3 ,
Elizabeth A l l i n w a n t e d t o talk t o Canadians
about her w o r k . For all her interest in
research that w a s done e l s e w h e r e - and
she had studied at Cambridge w i t h Ernest
Rutherford, a m o n g other luminaries - A l l i n
t h o u g h t it w r o n g that Canadian p h y s i c i s t s
should
meet
each other
chiefly
at
A m e r i c a n conferences. A s the secretary of
the CAP, she w o r k e d hard t o make the
organization a success and w a s proud of
the c o n t r i b u t i o n she made t o Canadian
physics t h r o u g h this w o r k . 2 3
W h e n Elizabeth A l l i n retired f r o m teaching
in 1 9 7 2 , she had earned the respect of her
colleagues and been made a full professor.
But, by then, she w a s the o n l y w o m a n
remaining on f a c u l t y in an increasingly
male d e p a r t m e n t . In the t w o years, 1 9 7 1
and ' 7 2 , the u n i v e r s i t y a w a r d e d
50
d o c t o r a t e s in physics. H o w m a n y of these
w e r e w o m e n is u n k n o w n , but I suspect
t h a t , in general, the number of w o m e n
d o c t o r a l candidates during the p o s t - W o r l d
W a r II years w a s not great. 2 4 M o r e
significant, perhaps, w a s the f a c t t h a t no
w o m e n w e r e recruited to the professoriate
during the years w h i c h A l l i n labelled " t h e
years of a f f l u e n c e " b e t w e e n 1 9 4 8 and
1 9 6 9 . A s she noted in her history of
physics
at
Toronto,
by
1970
the
department
had a professorial
staff
" n u m b e r i n g b e t w e e n s i x t y and s e v e n t y "
and the a t m o s p h e r e had g r e a t l y changed. 2 6
The small d e p a r t m e n t of less than a dozen
professors that had made Elizabeth A l l i n
and her colleagues feel so at home in the
1 9 3 0 s t h a t " w e felt as if w e o w n e d i t , " 2 6
had expanded m i g h t i l y . But it w o u l d appear
that
few
women
physicists
had
participated in this g r o w t h .
Recently, w o m e n have made a c o m e b a c k
as graduate s t u d e n t s in physics at
T o r o n t o . There have been, m o r e o v e r ,
struggles to hire and retain w o m e n f a c u l t y .
The reasons that these struggles have
proven so d i f f i c u l t and u n p r o d u c t i v e are
c o m p l e x and beyond the scope of the
present a c c o u n t . W h a t should be clear
f r o m this historical s k e t c h of w o m e n in the
physics d e p a r t m e n t at T o r o n t o , h o w e v e r ,
is that physics is far f r o m a "nont r a d i t i o n a l " subject for w o m e n in Canada.
Indeed, during the early decades of
T o r o n t o ' s d e v e l o p m e n t as a research
university,
women
were
very
much
present, d e m o n s t r a t i n g their talents as
both
undergraduates
and
graduate
s t u d e n t s in the field. Some w e r e even
a d m i t t e d t o the teaching ranks although,
w i t h the possible e x c e p t i o n of Elizabeth
Allin, they appear not t o have been g i v e n
the same opportunities at T o r o n t o as men.
If
physics
came
to
be
seen
as
" t r a d i t i o n a l l y " not a w o m e n ' s s u b j e c t , this
w a s a d e v e l o p m e n t belonging more t o the
second, t h a n the first half of the t w e n t i e t h
c e n t u r y . It appears t o have been a t t i t u d e s
t h a t developed, and changes in the c u l t u r e
and c o n d u c t of physics that o c c u r r e d
during the expansionist period after W o r l d
W a r II, that gave rise t o the false
impression t h a t , w i t h rare e x c e p t i o n s ,
w o m e n w e r e not at h o m e in the s u b j e c t .
W e need t o k n o w more about w o m e n like
Elizabeth Laird, Elizabeth Allin, and their
less w e l l - k n o w n f e m a l e colleagues. W h a t
w e r e the forces that made it possible for
some w o m e n t o succeed in p h y s i c s , w h e n
others
especially
in
subsequent
generations - w o u l d find it so d i f f i c u l t ? W e
need, especially, to look carefully at h o w
physics,
at T o r o n t o
and
elsewhere,
changed during the decades f o l l o w i n g the
Second W o r l d W a r , for it w a s in these
decades that the cultures and s t r u c t u r e s
t h a t g o v e r n c o n t e m p o r a r y physics w e r e
largely created. Even this brief appraisal of
the blocked careers of many of T o r o n t o ' s
95
early w o m e n physicists suggests that w e
should not f o c u s o n gender alone w h e n
making these explorations. Considerations
of g e n d e r m a y w e l l h a v e b e e n c o m p l i c a t e d
by marital status, ethnicity, and religion not t o m e n t i o n race, class and sexual
preference. The
records rarely
speak
d i r e c t l y t o t h e s e i s s u e s ; n o r are
we
necessarily at ease w i t h t h e m .
Thus
a n s w e r s t o t h e q u e s t i o n of w h y Elizabeth
Allin's female colleagues did not manage
t o m o v e u p t h r o u g h t h e r a n k s , as s h e d i d ,
m a y a l w a y s l a r g e l y e l u d e u s . But it is
•important
to
ask
this
question
n e v e r t h e l e s s . For a n e x a m i n a t i o n of t h e
l i v e s o f t h e s e w o m e n p h y s i c i s t s a l e r t s us
t o t h e k i n d s of c o n s t r a i n t s t h a t
may
c o n t i n u e t o b l o c k t h e a d v a n c e m e n t of
w o m e n in u n i v e r s i t y p h y s i c s i n o u r o w n
t i m e , as w e l l as t o t h e c o m p l e x i t y of t h e
prejudices and fears that prevent us f r o m
overcoming them.
W e cannot change the past, but w e can
t r y t o l e a r n f r o m it a n d , i n t h e c a s e of t h e
e a r l y h i s t o r y o f w o m e n in p h y s i c s at t h e
U n i v e r s i t y o f T o r o n t o , t h e r e is s o m e r e a s o n
t o be e n c o u r a g e d . T h a t w o m e n e a r n e d
n e a r l y o n e q u a r t e r of t h e P h . D ' s in p h y s i c s
t h a t w e r e a w a r d e d b y T o r o n t o in t h e f i r s t
t h i r d o f t h e 2 0 t h c e n t u r y is a n i m p o r t a n t
f a c t . E q u a l l y i m p o r t a n t is t h e f a c t t h a t
s e v e r a l o f t h e m , i n c l u d i n g at l e a s t o n e w h o
did not have a d o c t o r a t e , w e r e able to
w o r k in p h y s i c s at T o r o n t o d u r i n g t h e
m i d d l e y e a r s of t h e c e n t u r y , a l t h o u g h their
jobs w e r e sometimes insecure and almost
i n v a r i a b l y l o w - p a y i n g . F i n a l l y , t h e r e is t h e
encouraging
fact
that
o n e of
them,
Elizabeth Allin, had a well-recognized and
successful career, despite the apparently
less
welcoming
climate
for
women
p h y s i c i s t s at T o r o n t o d u r i n g the years t h a t
followed.
Archives, Elizabeth Laird Papers, "London
physicist acquainted w i t h the sting of
prejudice" The London Free Press, 21
April 1 9 6 7 . According t o the latter, Laird
had w o n the Mulock Scholarship in
Mathematics and Physics in her second
year and the American Association for
the Advancement of Science Scholarship
in her third year. The fellowship that she
was denied was the 1851 Exhibition
Scholarship. See also Mount Holyoke
College Archives, Elizabeth Laird Papers,
"Physicist Receives Honor," name of
paper illegible, 29 May 1 9 1 3 .
3.
A t the time, a number of Ontario
women's
colleges
offered
courses
equivalent t o the first year of study at a
university. OLC was one of several
Methodist institutions for young women
w h i c h had an affiliation w i t h Victoria
College and could prepare its students for
advanced standing at the University of
Toronto. See Johanna Selles-Roney, " ' A
Realm of Pure Delight': Methodists and
W o m e n ' s Education in Ontario, 18361 9 2 5 , " (Ed.D Dissertation, University of
Toronto, 1992).
4.
University
of
Toronto
Archives,
Newspaper Clippings Collection, A730 0 2 6 / 2 1 4 ( 10). The first quotation is from
" A Young Lady's Success: Toronto
Graduate of 1 8 9 6 Achieves Honour at
American
College,"
unidentified
newspaper, 16 March 1 9 9 8 ; the second
is from the 1 9 6 9 O w e n Sound obituary
cited in note 2.
5.
Newspaper clippings cited above. See
also University of Toronto Archives,
Clippings Collection, A 7 3 - 0 0 2 6 / 2 1 4 ( 1 0 )
"Noted Physicist Plans Her Second
Retirement," The Globe and Mail June
2 6 , 1 9 5 3 . Laird's research during the war
was chiefly on radar; after the war she
worked on " t h e effect of microwave
radiation...on
biological
materials."
Previously, she had worked in a variety of
areas, publishing approximately 3 0 papers
during the course of her career. One
official listing, appearing t o date from the
m i d - 1 9 3 0 s , reveals that the majority of
those published before 1 9 3 5 were in the
prestigious journal, Physical Review. The
same account noted that Laird was a
Fellow of both the American Physical
Society and the American Association for
the Advancement of Science. See clipping entitled "Physics" Mount Holyoke
College Archives, Elizabeth R. Laird
Papers.
ACKNOWLEDGEMENT
I w i s h t o a c k n o w l e d g e t h e s u p p o r t of t h e
Social Science and Humanities Research
Council
of
Canada for
the
research
r e p o r t e d in t h i s s t u d y . I a l s o w i s h t o t h a n k
C a t h y J a m e s , Penny Stephenson, and
A l y s o n King for their expert research
assistance in its preparation and the
journal's a n o n y m o u s reviewers for their
helpful c o m m e n t s on an earlier v e r s i o n .
REFERENCES
1.
2.
96
Marjorie R. Theobald, " W o m e n ' s Studies
in Colonial Victoria," Melbourne Studies
in Education ( 1989-90); Pnina G. Abir-am
and Dorinda Outram, eds. Uneasy Careers
and Intimate Lives: W o m e n in Science,
1 7 8 9 - 1 9 7 9 (New Brunswick and London:
Rutgers
University
Press,
1989);
Marianne Gosztonyi Ainley, ed. Despite
the Odds: Essays on Canadian W o m e n
and Science (Montreal: Véhicule Press,
1 9 9 0 ) . For an important monograph
dealing w i t h the United States, see
Margaret W . Rossiter, W o m e n Scientists
in America: Struggles and Strategies t o
1 9 4 0 (Baltimore and London: The Johns
Hopkins University Press, 1982).
University
of
Toronto
Archives,
Newspaper Clippings Collection, A730 0 2 6 / 2 1 4 ( 1 0 ) , "Dr. Elizabeth Laird born
here, outstanding physicist," obituary in
an unnamed Owen Sound newspaper, 8
April 1 9 6 9 , and Mount Holyoke College
Physics in C a n a d a
M arch/Aprill 9 9 6
6.
Margaret Prang, A Heart at Leisure from
Itself: Caroline Macdonald of Japan
(Vancouver: University of Vancouver
Press, 1 9 9 5 ) , especially chapter 1.
Caroline Macdonald stayed in contact
w i t h her physicist friends, however, and
later years would see her appealing t o
E.F. Burton, Toronto's head of physics
from 1 9 3 2 t o 1 9 4 8 , for assistance in her
efforts t o raise money in Toronto for her
Japanese mission.
7.
University of Toronto Archives, University
of Toronto Calendars and Directories.
Every year was examined up t o 1 9 4 0 - 4 1 .
I am grateful for the research assistance
of Penny Stephenson and Cathy James
for this part of the study.
8.
Published by the Physics Department in
1981.
9.
Alison Prentice, et al, Canadian Women:
A History (Toronto: Harcourt Brace
Jovanovich, 1988) Table A . 2 0 , p. 4 2 8 .
Although data available for 1 9 4 5 - 4 6
show the percentage of doctorates
granted t o women increasing t o 11.5 in
that year, the statistics by decade
indicate a general dropping off after
1 9 3 0 - 3 1 , in both degrees, w i t h w o m e n
not reaching these percentages again
until the 1960s or exceeding them until
1970-71.
10.
University administrative records show
Reed earning money typing for the
department as early as 1 9 0 6 , and in
various years prior t o 1 9 2 4 - 2 5 there are
items recording her pay for stenographic
and secretarial work. Reed was part of a
trend, for it appears t o have been during
the second and third decades of the 2 0 t h
century that University of Toronto
faculties and departments began t o add
secretaries t o their staff complements,
often choosing top w o m e n graduates for
these
positions.
Professor
Dorothy
Forward was one University of Toronto
scientist w h o resisted such an offer,
instead moving on t o graduate study and
a research and teaching career. See
Alison
Prentice,
"Bluestockings,
Feminists, or W o m e n Workers?
A
Preliminary
Look
at
Women's
Employment
at
the
University
of
Toronto," Journal of the Canadian
Historical Association (1991) 2 4 3 , 2 5 0
and 2 5 6 . For a brief discussion of Annie
Reed's importance t o the department, see
Allin, Physics at the University of
Toronto, 10.
11.
Allin, Physics
Toronto, 11.
12.
University
of
Toronto
Archives,
Newspaper Clippings Collection, A 7 3 0026/009(68)
Telegram, 6 October
1 9 3 6 . May Annetts' student card (UTA,
A 7 3 - 0 0 2 6 1 / 0 0 9 ( 6 8 ) showsherdeparture
from England, followed by many more
moves t o various Canadian cities, moves
w h i c h must have made the pursuit of her
physics career difficult. Alyson King has
nevertheless discovered one reference t o
her in the calendars of McGill, where she
is listed in 1 9 5 5 - 5 6 as a sessional
lecturer
in agricultural
physics
at
Macdonald College.
13.
Assistants and demonstrators appear t o
have
been
the
lowest
ranked
appointments, followed by instructor,
lecturer, and the various professorial
ranks. Presumably only the professorial
appointments carried tenure.
14.
Both Hogg and Ford were married t o
Toronto professors, as was Mossie May
Kirkwood (Professor of English and Dean
of Women at University College and,
later, Trinity). Yet Kirkwood felt some
discrimination because of her marriage.
See Prentice, "Bluestockings," 2 5 6 - 5 7 ;
Alison Prentice, "Scholarly Passion: T w o
W o m e n W h o Caught It," in Alison
Prentice and Marjorie R. Theobald, eds.,
W o m e n W h o Taught : Perspectives on the
History
of
Women
and
Teaching
(Toronto: University of Toronto Press,
1991), especially 2 6 9 - 7 2 .
1 5.
University of Toronto Directories; C.A.P.
membership list, Physics in Canada,
Supplement t o Volume 8, No. 2 (Winter
1952). I am indebted t o Alyson King,
w h o searched the directories and other
records t o document the careers of
Toronto's women Ph.Ds in the 1 9 4 0 s and
beyond.
at
(continued on page 100)
the
University
of
USING NONSEXIST LANGUAGE
L'UTILISATION D'UN LANGAGE NON-SEXISTE
by
par
Ruth King, York U n i v e r s i t y
Ruth King, York U n i v e r s i t y
Many changes are necessary for w o m e n to achieve equality and
visibility in s o c i e t y .
Considerable research has s h o w n t h a t
language plays an i m p o r t a n t role in c o n s t r u c t i n g social reality and
that sexist language has negative e f f e c t s for girls and w o m e n . For
instance, Briere and Lanktree ( 1 9 8 3 ) f o u n d that w o m e n rated a
career in p s y c h o l o g y as more or less a t t r a c t i v e in direct p r o p o r t i o n
t o the use of nonsexist or sexist language in the career d e s c r i p t i o n .
W h e n g e n d e r - e x c l u s i v e language w a s used, w o m e n w e r e less
interested in the career. D a y h o f f ' s 1 9 8 3 s t u d y of evaluations of
w o m e n running for political o f f i c e f o u n d that the use of sexist
language in the c a m p a i g n literature resulted in f e m a l e candidates
being m o r e negatively s t e r e o t y p e d . C r a w f o r d and English ( 1 9 8 4 )
f o u n d that w o m e n s t u d e n t s recall i n f o r m a t i o n more e f f i c i e n t l y
w h e n gender-inclusive t e r m s s u c h as people, his/her and he/she
are used. The scholarly literature, then, s h o w s that the idea that
language use is a trivial m a t t e r is incorrect.
Il reste plusieurs c h a n g e m e n t s à faire pour que les f e m m e s
atteignent l'égalité et la visibilité qui leur revient.
Plusieurs
recherches ont d é m o n t r é que le langage joue un rôle i m p o r t a n t
dans l ' é t a b l i s s e m e n t de la réalité sociale et q u ' u n langage sexiste
a des e f f e t s néfastes pour les jeunes filles et les f e m m e s . Par
exemple, Brière et Lanktree ( 1 983) ont t r o u v é que les f e m m e s ont
considéré une carrière en psychologie c o m m e étant plus ou moins
intéressante selon q u ' u n langage non-sexiste ou sexiste a été
utilisé dans la d e s c r i p t i o n de l ' e m p l o i . Les f e m m e s étaient moins
intéressées par la carrière lorsque le t e x t e n ' e m p l o y a i t que le genre
masculin. En 1 9 8 3 , l'étude de D a y h o f f c o n c e r n a n t l ' é v a l u a t i o n de
candidates à des élections en politique, a d é m o n t r é que l ' u t i l i s a t i o n
d ' u n langage sexiste dans la d o c u m e n t a t i o n de leurs campagnes
faisait en sorte que les candidates étaient s t é r é o t y p é e s plus
n é g a t i v e m e n t . C r a w f o r d et English ( 1 9 8 4 ) ont t r o u v é que les
étudiantes se rappellent plus e f f i c a c e m e n t de l ' i n f o r m a t i o n quand
une t e r m i n o l o g i e inclusive, c o m m e personnes, leur, et il/elle, est
utilisée. Donc, la littérature nous d é m o n t r e que l ' u t i l i s a t i o n d ' u n
langage est i m p o r t a n t e .
Forms of linguistic s e x i s m include the t r e a t m e n t of male-as-norm
(e.g. Each candidate should include three copies of his résumé
with
the application),
irrelevant reference t o gender (e.g. That
woman
physicist
is really
smart),
irrelevant reference t o physical
appearance or t o d o m e s t i c relationship (e.g. Jane Smith, wife of
the well-known
lawyer, Stephen Smith...), and inappropriate f o r m s
of address (e.g. Could you get me a copy of that report,
dear?).
Linguistic s e x i s m goes beyond w o r d choice and w h a t i n f o r m a t i o n
is included: for instance, research by N a n c y Henley et al ( 1 9 9 5 )
s h o w s that the use of the passive voice in n e w s media reports of
violence against w o m e n leads readers t o take the violence less
seriously.
Des f o r m e s de s e x i s m e linguistique incluent l ' u t i l i s a t i o n du genre
m a s c u l i n c o m m e norme (e.g. Chaque candidat doit s o u m e t t r e trois
copies de son c u r r i c u l u m vitae avec son application), une référence
superflue au sexe (e.g. Cette femme médecin est très
intelligente),
une référence superflue à l'apparence physique ou à la relation
d o m e s t i q u e (e.g. Aline Robert, femme du célèbre avocat,
Stéphane
Robert...),
et des f o r m e s d'adresse qui ne sont pas appropriées
(e.g. Pourrais-tu me chercher une copie de ce rapport, chérieP). Le
s e x i s m e linguistique n ' e x i s t e pas seulement dans le choix des m o t s
et dans l ' i n f o r m a t i o n incluse: par exemple, la recherche de Nancy
Henley et al (1 995) indique que l ' u t i l i s a t i o n de la voix passive dans
les rapports médiatiques sur la violence contre les f e m m e s amène
les lecteurs à considérer c e t t e violence c o m m e étant moins
sérieuse.
Here are s o m e suggestions for using nonsexist language, in w r i t i n g
and speaking. W h i l e I i d e n t i f y s o m e problematic practices and
suggest some solutions, I suggest that the reader consult a
c o m p r e h e n s i v e set of guidelines that o f f e r s a fuller d i s c u s s i o n of
the issues.
Voici quelques suggestions pour l ' u t i l i s a t i o n d ' u n langage nonsexiste, en écriture et dans la langue parlée. Quoique j ' i d e n t i f i e ici
quelques habitudes problématiques et quelques suggestions, je
vous suggère de consulter un guide c o m p l e t qui examine plus en
profondeur ce sujet.
(1)
Use parallel f o r m s of reference for w o m e n and men. For
e x a m p l e , do not cite a male scholar by s u r n a m e only and a w o m a n
scholar by first name plus surname; do not use a title to refer to or
address a male colleague but refer to or address a f e m a l e c o w o r k e r
by first name. In English, use Mr as a title for males and Ms as a
title for f e m a l e s , unless y o u are certain that a w o m a n prefers a
title w h i c h indicates marital status {Miss or Mrs).
(1)
Utiliser des t e r m e s de référence parallèle pour les
h o m m e s et les f e m m e s . Par exemple, ne pas citer un scientifique
seulement par son nom de famille et une scientifique par son
prénom avec son nom de famille. Ne pas v o u s adressez à un
collègue par son t i t r e en m ê m e t e m p s que vous vous adressez à
une consoeur par son prénom. En anglais, utiliser Mr. c o m m e t i t r e
pour les h o m m e s et /Ws.pour les f e m m e s , à moins que v o u s soyez
certain qu'elle préfère un t i t r e qui indique son statut marital ( M i s s
ou Mrs.).
(2)
In English, avoid so-called masculine generics such as the
pronoun he [his, etc.) w i t h s e x - i n d e f i n i t e a n t e c e d e n t s or m a n and
its c o m p o u n d s (except in u n a m b i g u o u s reference t o males). In
French, avoid l'homme and les hommes (except in u n a m b i g u o u s
reference t o males).
(2)
En anglais, éviter les titres masculins, soi-disant
générique, c o m m e le p r o n o m he (his, etc.) avec des antécédents
de genre indéfini ou man (sauf quand c ' e s t une référence nonambigue à un h o m m e ) . En français, éviter l'homme et les hommes
(toujours sauf si la référence est à un h o m m e ) .
(3)
In French, avoid so-called generic o c c u p a t i o n a l titles
(avocat, etc.). Use masculine ones w h e n referring t o a m a n and
their f e m i n i n e equivalent w h e n referring t o a w o m e n
(avocate).
W h e n sex is indefinite, use b o t h (les étudiants et les étudiantes
de
la première année, les étudiant(e)s,
etc.) Feminine equivalents for
masculine titles f o l l o w the regular g r a m m a t i c a l rules of the
language. A v o i d c o m p o u n d s w i t h femme (femme médecin, etc.)
w h i c h have the same c o n n o t a t i o n s as English c o m p o u n d s w i t h
lady or
woman.
(3)
En français, éviter les titres d ' o c c u p a t i o n , soi-disant
générique, (physicien, avocat, etc.). Utiliser les titres masculins en
référant à un h o m m e , et l'équivalent f é m i n i n en référant à une f e m m e
(physicienne,
avocate, etc.). Quand le sexe est indéfini, utiliser les
deux (les étudiants
et les étudiantes
de la première année, les
étudiant(e)s,
etc.) Les titres f é m i n i n s suivent les m ê m e s règles
g r a m m a t i c a l e s de la langue que les titres masculins. Éviter les
c o m p o s é s avec le m o t femme (femme médecin etc.), qui ont les
m ê m e s c o n n o t a t i o n s que les c o m p o s é s en anglais avec lady ou
woman.
(4)
In b o t h French and English, avoid using genuine generics
as if t h e y refer only to males (e.g. Many immigrants
come to
Canada each year.
Their wives have little access to
language
training.;
On peut utiliser le langage pour beaucoup de raisons discuter avec sa femme).
(4)
Dans les deux langues, éviter l ' u t i l i s a t i o n de vraies
expressions génériques c o m m e si elles ne référaient q u ' a u x
h o m m e s (On peut utiliser le langage pour beaucoup de raisons discuter avec sa f e m m e , par exemple; M a n y i m m i g r a n t s c o m e to
Canada each year. Their w i v e s have little access t o language
training).
97
(5)
In English, a v o i d adding m o d i f i e r s or s u f f i x e s t o nouns
t h a t m a r k sex u n n e c e s s a r i l y (e.g. woman professor,
stewardess).
(In French, t h e t e n d e n c y is t h e o p p o s i t e ; f e m i n i n e e q u i v a l e n t s are
preferred.)
(5) En anglais, éviter l'ajout de m o d i f i c a t i f s ou de s u f f i x e s aux
n o m s qui indiquent le sexe de f a ç o n superflue (e.g.
woman
professor,
stewardess).
En f r a n ç a i s , la t e n d a n c e est le c o n t r a i r e ;
en général l ' é q u i v a l e n t f é m i n i n est préféré.
Finally, it is i m p o r t a n t t o bear in m i n d t h a t s e x i s t ideas dressed u p
in n o n s e x i s t language r e m a i n s e x i s t . For e x a m p l e , using "the
worker...he
or she..." and "the researcher...he
or she..." m a y , in
s o m e cases, be an adequate linguistic s o l u t i o n , but unless
w o m e n ' s w o r k and w o m e n ' s needs are d i s c u s s e d in the
d o c u m e n t s c o n c e r n e d , those d o c u m e n t s r e m a i n s e x i s t .
Enfin, il est i m p o r t a n t de rappeler que les idées s e x i s t e s enrobées de
paroles n o n - s e x i s t e s d e m e u r e n t s e x i s t e s . Par e x e m p l e , en utilisant
" le physicien ou ta physicienne...
il ou elle... et "le/la
présidentfe)...
Helle..." on t r o u v e une s o l u t i o n adéquate au problème linguistique,
mais à m o i n s q u e le travail et les besoins des f e m m e s soit d i s c u t é
dans ces d o c u m e n t s , ces derniers d e m e u r e n t s e x i s t e s .
REFERENCES
RÉFÉRENCES
1.
Briere, J o h n and Cheryl Lanktree. 1 9 8 3 . "Sex Role Related Effects
of Sex Bias in Language" Sex Roles 9 : 6 2 5 - 3 2
1.
Briere, J o h n et Cheryl Lanktree, 1 9 8 3 . "Sex Role Related Effects of
Sex Bias in Language" Sex Roles 9 , 6 2 5 - 3 2 .
2.
C r a w f o r d , Mary and Linda English. 1 9 8 4 . "Generic Versus Specific
Inclusions of W o m e n in Language: Effects on Recall." Journal of
Psycholinquistic Research 1 3 : 3 7 3 - 8 1
2.
Crawford, Mary et Linda English, 1 9 8 4 . "Generic Versus Specific
Inclusions of W o m e n in Language: Effects on Recall." Journal of
Psycholinquistic Research 1 3 , 3 7 3 - 8 1 .
3.
D a y h o f f , Signe. 1 9 8 3 . "Sexist Language and Person Perception:
Evaluation of Candidates f r o m Newspaper Articles." Sex Roles 9 : 5 2 7 38
3.
D a y h o f f , Signe, 1 9 8 3 . "Sexist Language and Person Perception:
Evaluation of Candidates from Newspaper Articles." Sex Roles 9 ,
527-38.
4.
Henley,
Nancy,
Michelle
Miller
and J o Anne Beazley. 1 9 9 5 .
" S y n t a x , Semantics and Sexual Violence: Agency and the Passive
Voice." Journal of Language and Social Psychology 1 4 : 6 0 - 8 4
4.
Henley, Nancy, Michelle Miller et J o Anne Beazley, 1 9 9 5 . " S y n t a x ,
Semantics and Sexual Violence: Agency and the Passive Voice"
Journal of Language and Social Psychology 14, 6 0 - 8 4 .
A d d i t i o n a l references regarding g e n d e r - n e u t r a l language
D e s références additionelle c o n c e r n a n t le langage non-sexiste.
T a l k i n g Gender - A Guide t o N o n s e x i s t C o m m u n i c a t i o n , Ruth King,
C o p p Clark P i t t m a n Ltd, T o r o n t o , 1 9 9 1 .
T a l k i n g Gender - A Guide t o N o n s e x i s t C o m m u n i c a t i o n , Ruth King,
C o p p Clark P i t t m a n Ltd, T o r o n t o , 1 9 9 1 .
Pour u n genre à part entière: Guide pour la r é d a c t i o n de t e x t e s
n o n - s e x i s t e s . M i n i s t è r e de l ' é d u c a t i o n d u Q u é b e c , Q u é b e c , 1 9 8 8 .
Pour u n genre à part entière: Guide pour la r é d a c t i o n d e t e x t e s
n o n - s e x i s t o s . M i n i s t è r e de l ' é d u c a t i o n du Q u é b e c , Q u é b e c , 1 9 8 8 .
RENDERING T H E CAP BY-LAWS GENDER-NEUTRAL
by D. Poirier, INRS-Énergie et M a t é r i a u x
Original T e x t
Possible m o d i f i c a t i o n
Final V e r s i o n
" A n applicant for m e m b e r s h i p
m a y be a d m i t t e d as an a f f i l i a t e if
either
m a y be a d m i t t e d as an affiliate if
either
m a y be a d m i t t e d as an a f f i l i a t e if
the applicant either
(a)
he
does
not
fulfil
the
r e q u i r e m e n t s for m e m b e r s h i p as
g i v e n in S e c t i o n 2 but does
possess a degree of Bachelor of
A r t s , Bachelor of Science, or an
e q u i v a l e n t degree or d i p l o m a f r o m
a recognized i n s t i t u t i o n ;
(a) he or she does not f u l f i l the
r e q u i r e m e n t s for m e m b e r s h i p as
g i v e n in S e c t i o n 2 but does
possess a degree of Bachelor of
A r t s , Bachelor of Science, or an
equivalent degree or d i p l o m a f r o m
(a) does not f u l f i l the r e q u i r e m e n t s
for
m e m b e r s h i p as g i v e n
in
S e c t i o n 2 but does possess a
degree of
Bachelor of
Arts,
Bachelor
of
Science,
or
an
equivalent degree or d i p l o m a f r o m
or
(b)
he
holds
professional
m e m b e r s h i p in an a s s o c i a t i o n
a c c e p t a b l e for these purposes t o
the membership committee;
(b) he or she holds professional
m e m b e r s h i p in an a s s o c i a t i o n
acceptable for these purposes t o
the m e m b e r s h i p c o m m i t t e e ;
or
(b) holds professional m e m b e r s h i p
in an a s s o c i a t i o n acceptable for
these purposes to the m e m b e r s h i p
committee;
or
(c)
he
has
such
other
q u a l i f i c a t i o n s as C o u n c i l m a y f r o m
time to time decide."
or
(c) he or she has s u c h other
q u a l i f i c a t i o n s as Council m a y f r o m
time to time decide."
(c) has s u c h o t h e r q u a l i f i c a t i o n s
as C o u n c i l m a y f r o m t i m e t o t i m e
decide."
" T h e e l e c t e d o f f i c e r s of
the
A s s o c i a t i o n and t h e I m m e d i a t e
Past President shall c o n s t i t u t e the
Executive
Committee
of
the
C o u n c i l , hereinafter called " T h e
E x e c u t i v e " . In t h e event t h a t t h e
I m m e d i a t e Past President c a n n o t
serve he shall be replaced by t h e
most
recent
Past
President
available."
" T h e elected o f f i c e r s of
the
Executive
Committee
of
the
E x e c u t i v e " . In t h e event t h a t t h e
I m m e d i a t e Past President c a n n o t
serve he or she shall be replaced
by t h e m o s t recent Past President
available."
54 Physics in Canada
M arch/Aprill 9 9 6
" T h e elected o f f i c e r s of
the
Executive
Committee
of
the
Executive".
A n I m m e d i a t e Past
President w h o is unable t o serve
shall be replaced by the m o s t
recent Past President a v a i l a b l e . "
"The Executive Secretary or his
nominee shall be e m p o w e r e d t o
sign the b a n k ' s f o r m of s e t t l e m e n t
and release."
"The Executive Secretary or his or
her nominee shall be e m p o w e r e d
to sign the b a n k ' s f o r m of
s e t t l e m e n t and release."
"The Executive Secretary shall be
e m p o w e r e d t o sign the b a n k ' s
f o r m of s e t t l e m e n t and release,
and to delegate this a u t h o r i t y . "
"If a M e m b e r desires t o v o t e
proxies, he shall receive a ballot
on w h i c h the Executive Secretary
shall initial the n u m b e r of proxies
authorized."
"If a M e m b e r desires t o v o t e
proxies, he or she shall receive a
ballot on w h i c h the Executive
Secretary shall initial the number
of proxies a u t h o r i z e d . "
" A M e m b e r desiring t o v o t e
proxies shall receive a ballot on
w h i c h the Executive Secretary
shall initial the number of proxies
authorized."
" A l l n o m i n a t i o n s w h e t h e r made by
the N o m i n a t i n g C o m m i t t e e or by
individual
members
must
be
signed
by
two
members
sponsoring the nominee, w h o by
his signature agrees t o accept the
nomination."
individual
members
must
be
signed
by
two
members
sponsoring the nominee, w h o by
his or her signature agrees t o
accept the n o m i n a t i o n . "
individual
members
must
be
signed
by
two
members
sponsoring the n o m i n a t i o n , and
also by the nominee, w h o t h u s
accepts the n o m i n a t i o n . "
" M a r k e d ballots m u s t be enclosed
in a plain u n m a r k e d envelope
w h i c h m u s t be sealed by the
v o t i n g m e m b e r and returned by
mail t o the Executive Secretary t o
reach him on or before M a y
30th."
mail t o the Executive Secretary t o
reach him or her on or before M a y
30th."
mail t o reach the
Executive
Secretary on or before
May
30th."
LA MODIFICATION DE LA CONSTITUTION DE L'ACP POUR LA RENDRE NON-SEXISTE
par D. Poirier, INRS Énergie-Matériaux
T e x t e original
M o d i f i c a t i o n possible
V e r s i o n finale
"Un
candidat
peut
devenir
m e m b r e affilié s'il remplit l'une
des c o n d i t i o n s s u i v a n t e s : "
"Un(e) candidate(e) peut devenir
m e m b r e affilié si il/elle remplit
l'une des conditions s u i v a n t e s "
" T o u t e personne peut devenir
m e m b r e affilié si elle remplit l'une
des conditions s u i v a n t e s : "
" T o u t e d e m a n d e d ' a d m i s s i o n doit
être faite au secrétaire exécutif à
l'aide de la f o r m u l e prescrite, ainsi
q u ' i l est prévu ci-après, et indiquer
la catégorie de m e m b r e s à laquelle
le candidat veut appartenir."
" T o u t e demande d ' a d m i s s i o n doit
être faite au/à
la
secrétaire
exécutif(ive) à l'aide de la f o r m u l e
prescrite, ainsi q u ' i l est prévu ciaprès, et indiquer la catégorie de
membres
à
laquelle
le/la
candidat(e) veut appartenir."
" T o u t e demande d ' a d m i s s i o n doit
être faite au secrétariat à l'aide de
la f o r m u l e prescrite, ainsi q u ' i l est
prévu ci-après, et indiquer la
catégorie de m e m b r e s à laquelle la
personne veut a p p a r t e n i r . "
" A p r è s avoir étudié les titres et
qualités des c a n d i d a t s , le C o m i t é
d'admission doit:
qualités
des
candidats
et
candidates, le C o m i t é d ' a d m i s s i o n
doit:
qualités de chaque candidat(e), le
C o m i t é d ' a d m i s s i o n doit:
(a) a d m e t t r e le candidat dans la
catégorie
indiquée
dans
la
demande;
(a) a d m e t t r e le/la candidat(e) dans
la catégorie indiquée dans la
demande;
(a) lui a d m e t t r e dans la catégorie
indiquée dans la d e m a n d e ;
ou
(b) d e m a n d e r au candidat de faire
partie d ' u n e autre catégorie;
ou
(b) demander au candidat ou
candidate de faire partie d ' u n e
autre catégorie;
(c) i n f o r m e r le candidat des autres
conditions
qu'il
doit
remplir,
c o n f o r m é m e n t aux d i s p o s i t i o n s et
normes énoncées à l ' A r t i c l e III."
(c) i n f o r m e r le/la candidat(e) des
autres conditions q u ' i l ou elle doit
remplir, c o n f o r m é m e n t aux dispositions et normes énoncées à
l ' A r t i c l e III."
Quatre d i r e c t e u r s représentent les
diverses catégories de m e m b r e s ,
à savoir:
Quatre
d i r e c t e u r s (t r ic e s)
représentent
les
diverses
catégories de m e m b r e s , à savoir:
La d i r e c t i o n
représentant
les
diverses catégories de m e m b r e s
c o m p r e n d q u a t r e postes, à savoir:
un Directeur des m e m b r e s élu par
les
membres
titulaires
de
l'Association;
un(e) D i r e c t e u r ( t r i c e ) d e s m e m b r e s
élu(e) par les m e m b r e s titulaires
de l ' A s s o c i a t i o n ;
le poste de Directeur des m e m b r e s
élu par les m e m b r e s t i t u l a i r e s d e
l'Association;
(b) lui demander e faire
d ' u n e autre catégorie;
partie
ou
(c)
lui
informer
des
autres
conditions
à
remplir,
c o n f o r m é m e n t aux d i s p o s i t i o n s et
normes énoncées à l ' A r t i c l e III.
99
un Directeur des m e m b r e s affiliés
é l u par les m e m b r e s a f f i l i é s d e
l'Association;
a f f i l i é s élu(e) par les m e m b r e s
affiliés de l'Association;
le p o s t e d e D i r e c t e u r d e s m e m b r e s
a f f i l i é s élu par les m e m b r e s a f f i l i é s
de l'Association;
u n D i r e c t e u r - é t u d i a n t é l u par les
m e m b r e s
étudiants
de
l'Association;
un(e)
Directeur(trice)-étudiantle)
élu(e) par les m e m b r e s é t u d i a n t s
de l'Association;
le p o s t e d e D i r e c t e u r - é t u d i a n t é l u
par les m e m b r e s é t u d i a n t s d e
l'Association;
et
un
Directeur
des
membres
c o r p o r a t i f s élu par les m e m b r e s
corporatifs de l'Association."
et
c o r p o r a t i f s élu(e) par les m e m b r e s
corporatifs de l'Association."
et
le p o s t e d e D i r e c t e u r d e s m e m b r e s
c o r p o r a t i f s élu par les m e m b r e s
corporatifs de l ' A s s o c i a t i o n . "
"Les mandats du président, du
secrétaire-trésorier honoraire et
des quatre directeurs sont d'une
année.
Le v i c e - p r é s i d e n t
élu
succède
automatiquement
au
vice-président."
" L e s m a n d a t s d u p r é s i d e n t o u d e la
présidente, du secrétaire-trésorier
h o n o r a i r e o u d e la s e c r é t a i r e t r é s o r i ô r e et d e s q u a t r e d i r e c t e u r s
ou directrices sont d ' u n e année.
Le v i c e - p r é s i d e n t é l u o u la v i c e
présidente
élue
succède
automatiquement
au
vicep r é s i d e n t o u à la v i c e p r é s i d e n t e .
"Les mandats des postes
de
président,
de
s.-t.h.
et
de
direction sont d'une année.
Le
v i c e - p r é s i d e n t é l u o u la v i c e présidente
élue
succède
automatiquement
au
vicep r é s i d e n t o u à la v i c e - p r é s i d e n t e . "
The
Early
History
of
W o m e n . . . by
A . Prentice (continued f r o m pg. 96)
16.
1 7.
18.
19.
20.
Rachel Schlesinger, "Volunteers for a
Dream," Canadian J e w i s h Historical
Society Journal 1, 1 (Fall 1988)
especially p. 3 1 . M a t t i e Rotenberg
was active in Hadassah-Wizo, w h i c h
is the subject of Schlesinger's article.
Cohen's career at Mount H o l y o k e l e f t
f e w traces in the Mount Holyoke
College Archives, apart from notices
of her appointment and eventual
release from employment. There are
occasional
references
to
her,
however, in the papers of Mildred
Allen, her colleague in the physics
department at the college. See also
University of Toronto Archives,
Newspaper
Clippings
Collection,
A73-0026/064(17),
"National
Research Report 1 9 3 0 " for a brief
account of her early research.
Stephen Speisman documents " t h e
gradual
intensification
of
antisemitism in Ontario" from 1 9 3 3 into
the early years of World War II - just
the period w h e n Elizabeth Cohen and
Mattie Rotenberg w o u l d have been
trying t o gain a foothold in physics at
Toronto.
See
Speisman,
"Antisemitism
in
Ontario:
The
T w e n t i e t h Century," in Alan Davies,
ed. Antisemitism in Canada: History
and Interpretation (Waterloo: Wilfrid
Laurier Press, 1992) 1 2 5 - 2 9 . See
also Irving Abella, "Anti-Semitism in
Canada in the Interwar Years," in
The J e w s of North America, ed.
Moses Rischin (Detroit: W a y n e State
University Press, 1 9 8 7 ) .
University of T o r o n t o Archives,
Newspaper
Clippings
Collection,
A 7 3 - 0 0 2 6 / 3 7 1 (08) Telegram, 13
September 1 9 4 1 , " M a d e Professors
at the University of Toronto." " M i s s
K.M.
Crossley's
work
is
in
mechanics, hydrostatics and heat;
Miss E. J . Allin is an authority on
modern developments in physics,
especially
spectroscopy
and
problems having t o do w i t h
the
structure of the atom; Miss F. M.
Quinlan is in charge of the teaching
of physics t o household science and
music students." See also Allin,
Physics, 3 4 .
University of Toronto Archives, Oral
History Collection, B 9 3 - 0 0 3 5 , Karen
Fejer's interviews w i t h Elizabeth
Allin, Toronto, May-June, 1993.
21.
22.
Elizabeth Allin refers t o the pressure
on married w o m e n t o resign in
Physics at the University of Toronto,
25. In a 1 9 9 1 interview, Professor
Allin was more forceful in expressing
her view that bias against married
w o m e n during the Depression was
used as an excuse t o " c u t the s t a f f "
and "get rid of the w o m e n " at
Toronto. Author's interview w i t h
Elizabeth Allin, Toronto, May 1 9 9 1 .
2 5 . Allin, Physics, chapter 4 and p. 6 2 .
Not only had no w o m e n been hired,
it would also appear that all of Allin's
female colleagues had either retired
or left the department by the end of
the 1 9 5 0 s .
2 6 . Author's interview w i t h
Allin, May 1 9 9 1 .
Allin, Physics at
the University
of Toronto, 3034, and author's
interview with
Elizabeth Allin,
May 1991.
23.
A u t h o r ' s
interview w i t h
ElizabethAllin,
May
1991;
Karen Fejer's
interview,
M ay -J u n e
1993.
24.
Allin, Physics
a t
t h e
University of
T o r o n t o ,
Appendix 3 , p.
7 7 . Allin lists
the recipients
of doctorates
by year, but
only
initials
are given. To
discover
the
exactnumbers
of
women,
one
would
need t o go the
university
directories, as
I have been
able t o do only
for the years
prior t o 1 9 4 0 41.
MTF!
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HARVARD
A P P A R A T U S
C A N A D A
TEL: (514) 335-0792,1-800-361-1905
Physics in C a n a d a
M arch/Aprill 9 9 6
I m a g e
S c i e n c e
FAX: (514) 335-3482, 1-800-335-0792
E-MAIL 102263.2131@compuserve. com
100
Elizabeth
Physics in Canada /
Vol. 52, No. 2
1996 March/April
mars/avril 1996
Physics and Education
La Physique et Veducation
SOME W O M E N PHYSICISTS IN CANADA
SHMÉdlflKSL
Individual and Family Profiles
Featuring:
"The CAP 1994 Income Survey" by R.E. Green
"Women Physics Faculty in Canada" by J.B. Lagowski and J. McKenna
"Women Students in Physics in Canada: A Decade of Progress" by A.C. McMillan and E. Svensson
"WES-Women in Engineering and Science: A Canadian Success Story at NRC" by M. D'lorio
"The
Committee on the Status of Women in Physics of the American
L. Martinez-Miranda
Individual and Family Profiles of Women Physicists in Canada
Physical Society"
by
Canadian Association of Physicists
Association canadienne des physiciens et physiciennes
Institutional Members II Membres institutionels
(Physics Departments // Départements de physique)
Acadia University
Bishop's University
Brandon University
Brock University
Camosun College
Carleton University
CEGEP Beauce-Appalaches
CEGEP de Chicoutimi
CEGEP Francois-Xavier-Garneau
Collège Jean-de-Brébeuf
Collège Montmorency
Concordia University
Dalhousie University
École Polytechnique
Lakehead University
Laurentian University
Le Petit Séminaire de Québec
McGill University
McMaster University
Memorial University of Newfoundland
Mount Allison University
Okanagan University College
Queen's University
Royal Military College, Kingston
Saint Mary's University
St. Francis Xavier University
Simon Fraser University
Trent University
University of Alberta
University of British Columbia
University of Calgary
University of Guelph
Université Laval
University of Lethbridge
University of Manitoba
Université de Moncton
Université de Montréal
University of New Brunswick
University of Northern B.C.
University of Ottawa
University of Prince Edward Island
Université du Québec à Chicoutimi
Université du Québec à Montréal
Université du Québec à Trois-Rivières
University of Regina
University of Saskatchewan
Université de Sherbrooke
University of Toronto
University of Victoria
University of Waterloo
University of Western Ontario
University of Windsor
University of Winnipeg
Wilfrid Laurier University
York University
1 9 9 6 Sustaining Members // Membres de Soutien 1 9 9 6
(as at 1996 March 31)
A. John Alcock
H.R. Andrews
J. Brian Atkinson
C. Bruce Bigham
Bertram N. Brockhouse
Laurent G. Caron
Allan I. Carswell
Robert L. Clarke
Walter G. Davies
Gerald Dolling
Gordon W.F. Drake
Earl J. Fjarlie
Brian C. Gregory
Geoffrey C. Hanna
Elmer H. Hara
Akira Hirose
Roger Howard
David D. Isaak
Thomas E. Jackman
Allan E. Jacobs
J. Larkin Kerwin
James D. King
Ron M. Lees
Roger A. Lessard
A. David May
Jasper S.C. McKee
Ann C. McMillan
Jean-Louis Meunier
Elizabeth J. Nicol
Allan A. Offenberger
Roger Philips
Satti Paddi Reddy
Beverly E. Robertson
Lyle P. Robertson
John M. Robson
Donald W.L. Sprung
Alec T. Stewart
Boris P. Stoicheff
Eric C. Svensson
John G.V. Taylor
Henry M. Van Driel
Paul S. Vincett
Erich Vogt
THE CAP 1 9 9 4 INCOME SURVEY
by
TABLE la: SALARY INCOME
Ralph E. Green
Retired M e m b e r
The CAP received 4 1 7 responses t o the 1 9 9 4 Income Survey.
There w e r e 3 2 4 responses w i t h a salary i n c o m e , 51 w i t h a
pension i n c o m e , 3 4 w i t h a c o n s u l t i n g i n c o m e , and 5 2 w i t h a
scholarship i n c o m e .
A n o v e r v i e w of the salary i n c o m e is provided by the h i s t o g r a m ,
w h i c h c o v e r s the 3 2 4 responses w i t h a salary i n c o m e . All the
respondents did not provide a year of g r a d u a t i o n . For those w h o
d i d , the responses are analyzed in the f o l l o w i n g 2 0 tables.
Tables l a t o 1d s h o w the results for the four sources of i n c o m e .
There w e r e 3 1 6 responses w i t h salary i n c o m e , 4 7 w i t h pension
i n c o m e , 3 3 w i t h c o n s u l t i n g i n c o m e , and 5 0 w i t h s c h o l a r s h i p
income. The salary data are analyzed in more detail in the
f o l l o w i n g 16 tables.
Tables 2a t o 2c s h o w the results according t o the q u a l i f i c a t i o n s
of the respondents. There w e r e 13 responses w i t h a b a c h e l o r ' s
degree, 2 5 w i t h a m a s t e r ' s degree, and 2 7 7 w i t h a d o c t o r a t e
degree.
Tables 3a t o 3e c o v e r the areas of current e m p l o y m e n t . There
w e r e 1 8 6 responses f r o m the academic s e c t o r , 6 6 f r o m
g o v e r n m e n t agencies, 38 f r o m i n d u s t r y , 9 f r o m graduate
s t u d e n t s , and 13 f r o m other areas.
Tables 4a t o 4f c o v e r the geographic region of e m p l o y m e n t .
There w e r e 2 9 responses f r o m the A t l a n t i c Provinces. 7 0 f r o m
Quebec, 1 2 2 f r o m Ontario, 3 2 f r o m the Prairie Provinces, 35
f r o m British C o l u m b i a and the Territories, and 21 f r o m outside
Canada.
Lower
Quartile
<k$)
Upper
Quartile
<k$>
Year of
Graduation
Number
40-44
45-49
50-54
55-59
60-64
65-69
70-74
75-79
80-84
85-89
90-94
1
3
11
43
52
49
39
33
39
21
25
85.3
78.4
77.5
73.8
57.3
54.8
43.5
42.2
23.0
75 . 0
93.0
92.0
82.0
81.0
70.0
65.0
50.0
46 . 9
34.5
99 . 1
100.0
93.0
89.2
77 . 6
75.0
60.0
51.2
44 . 3
40-94
316
52.0
72 . 0
85.0
Median
<k$)
TABLE lb: PENSION INCOME
Year of
Graduation
Number
Lower
Quartile
<k$>
25-29
30-34
35-39
40-44
45-49
50-54
55-59
60-64
65-69
1
3
1
7
12
13
6
2
2
52.2
40.5
40.0
25-69
47
Median
<k$>
Upper
Quartile
<k$)
52.0
-
68 . 0
50.0
45.0
38.5
70.0
58.2
51.8
-
40.0
48.0
57 . 9
Tables 5a and 5b s h o w the results by gender. There w e r e 2 9 1
responses f r o m males and 18 f r o m females.
In each table, the medians and quartiles are g i v e n f r o m five-year
periods, based on the year of g r a d u a t i o n w i t h a Bachelor of
Science degree. The final e n t r y in a table c o v e r s the entire
period of that table. The medians are not reported if there are
less t h a n three responses in period, to m a i n t a i n c o n f i d e n t i a l i t y
of the i n c o m e s . The quartiles are reported only if there are
seven, or m o r e , responses in a period.
The C A P w i s h e s t o thank all those w h o responded to the s u r v e y
request, and w e l c o m e s s u g g e s t i o n s for i m p r o v i n g f u t u r e
surveys.
40
30
-
TABLE lc: CONSULTING INCOME
Year of
Graduation
Number
40-44
45-49
50-54
55-59
60-64
65-69
70-74
75-79
80-84
85-89
2
3
6
5
4
4
4
1
3
1
40-89
33
Lower
Quartile
<k$)
Median
<k$>
Upper
Quartile
<k$)
3.0
7.5
4.5
4.5
8.5
35.0
-
2.8
2.6
6.0
14.4
rfl
in
TABLE Id: SCHOLARSHIP INCOME
«
20
Year of
Graduation
œ
-Q
E
o
Z
T l rr.
0
10
20
30
40
50
60
70
80
90
100
110
Lower
Quartile
(kS)
Median
Upper
Quartile
<k$>
<k$)
75-79
80-84
85-89
90-94
1
1
7
41
13.8
13.0
15.0
16.0
17 . 6
20.0
75-94
50
13.0
15.6
19.2
-
120>125
Salaries (K$)
Histogram of 3 2 4 salary responses t o the
CAP 1 9 9 4 Income Survey
103
TABLE 2a: QUALIFICATIONS: BACHELOR'S DEGREE
Year of
Graduation
Number
65-69
70-74
75-79
80-84
85-89
90-94
1
1
1
1
2
7
65-94
13
Upper
Quartile
<k$>
Median
<kS>
Number
50-54
55-59
65-69
70-74
75-79
80-84
85-89
90-94
1
1
3
3
7
2
3
5
50-94
25
Year of
Graduation
Number
Lower
Quartile
<k$>
Median
<k$)
Upper
Quartile
(k$)
45-49
55-59
60-64
65-69
70-74
75-79
80-84
85-89
90-94
1
6
14
12
11
9
7
1
5
74.0
70.8
67.5
64.2
52.5
94.9
77.6
77.5
69.0
67.0
60.0
80.4
84.0
71.0
71.2
62.0
45-94
66
62.0
-
3.5
20.0
33.2
17.0
40.5
58.8
Lower
Quartil
(k$)
Median
(k$)
-
46.3
70.0
79.0
Upper
Quartile
<k$)
TABLE 3c: CURRENT EMPLOYMENT: INDUSTRY
-
61.5
71.7
52.0
67.0
76.5
-
46.0
24.0
40.0
52.0
71.8
TABLE 2c: QUALIFICATIONS: DOCTORATE DEGREE
Year of
Graduation
TABLE 3b: CURRENT EMPLOYMENT: GOVERNMENT
QUALIFICATIONS: MASTER'S DEGREE
TABLE 2b
Year of
Graduation
Lower
Quartile
<k$>
Number
Lower
Quartile
<k$>
Median
<kS>
Upper
Quartile
<M)
40-44
45-49
50-54
55-59
60-64
65-69
70-74
75-79
80-84
85-89
90-94
1
3
10
41
52
45
35
25
36
16
13
85.0
78.8
77.5
75.0
66.2
54.0
43.0
42.5
38.6
75.0
92.9
91.0
82.0
82.0
70.0
62.5
50.0
48.3
44.0
96.6
99.2
93.0
89.2
79.5
74.2
60.0
52.0
47.6
40-94
277
54.0
75.0
86.7
Year of
Graduation
Number
40-44
50-54
55-59
60-64
65-69
70-74
75-79
80-84
85-89
90-94
1
2
1
1
9
3
5
6
5
5
40-94
38
Lower
Quartile
<k»>
Median
<k$)
Upper
Quartile
(k$>
-
73.8
85.0
82.0
80.0
56.5
46.0
40.0
122.5
45.0
60.3
85.0
TABLE 3d: CURRENT EMPLOYMENT: GRADUATE
Year of
Graduation
Lower
Quartile
<kS)
65-69
75-79
90-94
Median
<k$)
Upper
Quartile
(k$)
54.8
2.5
TABLE 3a: CURRENT EMPLOYMENT: ACADEMIC
Year of
Graduation
Number
45-49
50-54
55-59
60-64
65-69
70-74
75-79
80-84
85-89
90-94
45-94
104
Lower
Quartile
(kS)
Median
( k$ )
Upper
Quartile
( k$ )
2
9
36
37
23
18
14
25
11
11
85.8
81.5
80.0
75.0
60.0
54.0
41.8
41.0
24.8
93.0
92.0
85.0
82.4
70.0
61.8
50.0
46.0
31.0
97.4
98.0
95.2
93.8
76.5
74.0
53.5
50.8
41.5
186
53.0
76.0
92.0
Physics in Canada
M arch/Aprill 9 9 6
TABLE 3e: CURRENT EMPLOYMENT: OTHER
Year of
Graduation
Number
65-69
70-74
75-79
80-64
85-89
2
6
1
1
3
65-89
13
Lower
Quartile
<k$)
Median
( k$ )
Upper
Quartile
(k$)
66.1
_
_
50.0
50.0
55.0
84.2
TABLE 4a: EMPLOYMENT REGION: ATLANTIC PROVINCES
Year of
Graduation
Number
50-54
55-59
60-64
65-69
70-74
75-79
80-84
2
5
8
5
3
3
3
50-84
29
Lower
Quartile
(k$)
70.9
61.5
Median
<k$>
Upper
Quartile
(k$)
83.0
75.8
75.0
70.0
49.5
42 . 0
79.2
75.0
82 . 6
TABLE 4e: EMPLOYMENT REGION: BRITISH COLUMBIA AND TERRITORIES
Year of
Graduation
Number
50-54
55-59
60-64
65-69
70-74
75-79
80-84
85-89
90-94
2
8
6
6
2
3
5
1
2
50-94
35
Lower
Quartile
<k$>
Median
(kS)
67.6
Upper
Quartile
(kS)
100.0
92.7
87 . 8
76.9
67.0
50.0
-
55.3
89.2
74.0
TABLE 4b: EMPLOYMENT REGION: QUEBEC
TABLE 4f: EMPLOYMENT REGION: OUTSIDE CANADA
Year of
Graduation
Number
40-44
50-54
55-59
60-64
65-69
70-74
75-79
80-84
85-89
90-94
1
1
5
8
11
13
9
9
8
5
40-94
70
Lower
Quartile
<k$)
Median
(kS)
Upper
Quartile
( k$ )
Year of
Graduation
Number
Lower
Quartile
<k$)
Median
<k$)
Upper
Quartile
( k$ )
-
81.5
71.1
65.9
53.5
48.0
48.0
90.0
82.0
80.0
75.0
60.0
53.0
51.0
40.0
83.0
84.0
80.5
72.8
61.6
56.5
52.0
67.5
81.0
50-54
60-64
65-69
70-74
75-79
80-84
85-89
90-94
2
4
2
2
1
3
4
3
50-94
21
119.0
-
-
51.7
48 . 3
34.5
80.0
128.6
Median
<k$)
Upper
Quartile
(kS)
85.3
79 . 5
77 . 5
74 . 5
56.4
55.2
43.5
44.8
27.0
75.0
93.0
91.5
82.0
81.0
70.0
65.0
51.8
49 .5
40.0
99. 1
100.0
93.0
89.0
78.5
74 . 8
60.0
52.2
46.3
54.0
75.0
86.0
46.7
TABLE 4c: EMPLOYMENT REGION: ONTARIO
TABLE 5a: GENDER: MALE
Year of
Graduation
Number
Lower
Quartile
<kS>
Median
( k$ )
45-49
50-54
55-59
60-64
65-69
70-74
75-79
80-84
85-89
90-94
2
1
19
20
20
17
12
13
6
12
80.6
75.9
76.5
64.5
62.4
47.2
35.0
22.0
95.0
81.2
84.0
69 . 0
68.8
55.0
45.0
37.0
45-94
122
54.0
75.0
Upper
Quartile
(kS)
-
101.5
93.5
87.0
76.5
75.0
60.5
49.5
45.2
85.0
Year of
Graduation
Number
40-44
45-49
50-54
55-59
60-64
65-69
70-74
75-79
80-84
85-89
90-94
1
3
11
40
52
46
37
31
35
17
18
40-94
291
Lower
Quartile
(k$>
TABLE 4d: EMPLOYMENT REGION: PRAIRIE PROVINCES
Year of
Graduation
Number
45-49
50-54
55-59
60-64
65-69
70-74
75-79
80-84
85-89
90-94
1
3
4
6
4
2
4
4
1
3
45-94
32
Lower
Quartile
(k$)
Median
<k$)
Year of
Graduation
_
94.0
94.0
93.0
116.0
-
67.5
49.5
-
27.0
48.5
76.1
TABLE 5b: GENDER: FEMALE
Upper
Quartile
(kS)
95.0
Number
65-69
70-74
75-79
80-84
85-89
90-94
3
1
1
3
4
6
65-94
18
Lower
Quartile
(kS)
Median
(kS)
Upper
Quartile
(kS)
85.0
-
45.0
42.5
20.5
34.5
45.0
60.0
105
WOMEN PHYSICS FACULTY IN CANADA
S u m m a r y of R e s u l t s of a S u r v e y S p o n s o r e d b y t h e C a n a d i a n A s s o c i a t i o n of P h y s i c i s t s
by
J o l a n t a B. L a g o w s k i , D e p t of P h y s i c s , M e m o r i a l U n i v e r s i t y of N e w f o u n d l a n d , St. J o h n ' s , N F L D , A 1 B 3 X 7
a n d J a n i s M c K e n n a , D e p a r t m e n t of P h y s i c s , U n i v e r s i t y of B r i t i s h C o l u m b i a , V a n c o u v e r , BC, V 6 T 1 Z 1
INTRODUCTION
A
recent
international s t u d y d )
of
w o m e n in p h y s i c s s h o w e d t h a t t h e
r e p r e s e n t a t i o n of w o m e n in p h y s i c s
d e p a r t m e n t s at t h e f a c u l t y level r a n g e s
w i d e l y - f r o m a h i g h of 4 7 %
in
H u n g a r y , 2 3 % in F r a n c e , Italy a n d
T u r k e y , 6 % in t h e N e t h e r l a n d s a n d N e w
Z e a l a n d , t o s u r p r i s i n g l y l o w v a l u e s of
3 % in Korea a n d t h e U . S . A . A l s o , in
g e n e r a l , as t h e e d u c a t i o n a l d e g r e e level
i n c r e a s e s , t h e p r o p o r t i o n of w o m e n in
physics decreases.(2) This p h e n o m e n o n
is o f t e n r e f e r r e d t o in t h e A m e r i c a n
l i t e r a t u r e as t h e " l e a k y p i p e l i n e " . ( 2 )
A t t h e 1 9 9 5 C a n a d i a n A s s o c i a t i o n of
P h y s i c i s t s (CAP) C o n g r e s s h o s t e d by
L a v a l U n i v e r s i t y in Q u e b e c , a n e v e n i n g
s e s s i o n o n W o m e n in P h y s i c s w a s
arranged, and a m o n g the presentations
w e r e r e s u l t s of s e v e r a l s u r v e y s of
w o m e n in p h y s i c s .
Several congress
participants
asked
how
Canada
compares w o r l d w i d e w i t h respect t o
t h e s e s t a t i s t i c s , as C a n a d a w a s not
l i s t e d in t h e i n t e r n a t i o n a l c o m p a r i s o n
studyd).
Apparently, statistics
have
not p r e v i o u s l y b e e n c o l l e c t e d r e g a r d i n g
the
number
of
women
in
faculty
p o s i t i o n s in p h y s i c s d e p a r t m e n t s in
Canadian academic institutions.
S p o n s o r e d by C A P , a s i m p l e s u r v e y
w a s d i s t r i b u t e d in order t o e s t i m a t e t h e
n u m b e r of f e m a l e f a c u l t y in C a n a d i a n
physics d e p a r t m e n t s . This survey w a s
n e v e r i n t e n d e d t o be as e x h a u s t i v e as
t h a t p e r f o r m e d by t h e C o m m i t t e e o n
the Status
of W o m e n
in
Physics
(CSWP) of
The American
Physical
S o c i e t y , but it is a f i r s t a t t e m p t t o
present quantitative data on w o m e n
p h y s i c i s t s in C a n a d a . A brief s u m m a r y
of t h e r e c e n t f e m a l e p h y s i c s g r a d u a t e s
(at t h e B . S c . a n d P h . D . levels) is also
given.
TABLE 1 : THE SURVEY MAILED TO CAP PHYSICS INSTITUTIONS.
1.
Does y o u r i n s t i t u t e grant P h D ' s in p h y s i c s ?
2.a.
H o w m a n y s t u d e n t s h a v e r e c e i v e d a BSc in p h y s i c s
f r o m your department from 1993-95?
2.b.
Of t h e s e BSc g r a d u a t e s , h o w m a n y w e r e f e m a l e ?
3.a.
H o w m a n y s t u d e n t s h a v e r e c e i v e d a PhD in p h y s i c s
f r o m your department f r o m 1993-95?
3.b.
Of t h e s e PhD g r a d u a t e s , h o w m a n y w e r e f e m a l e ?
4.a.
H o w m a n y f a c u l t y m e m b e r s are p r e s e n t l y in
your department?
4.b.
Of t h e s e f a c u l t y m e m b e r s , h o w m a n y are f e m a l e ?
4.C.
H o w m a n y t e n u r e d f a c u l t y m e m b e r s are p r e s e n t l y
in y o u r d e p a r t m e n t ?
4.d.
H o w m a n y f e m a l e t e n u r e d f a c u l t y m e m b e r s are
p r e s e n t l y in y o u r d e p a r t m e n t ?
4.e.
H o w m a n y t e n u r e - t r a c k f a c u l t y m e m b e r s are
4.f.
H o w m a n y f e m a l e t e n u r e - t r a c k f a c u l t y m e m b e r s are
4.g.
If 4f + 4 d does not e q u a l 4 b , or if 4 c + 4 e d o e s not equal 4 a , please s t a t e
discrepancy.
5.
If y o u h a v e any c o m m e n t s o n w o m e n in p h y s i c s issues t h a t y o u ' d like t o
s h a r e w i t h us, please f e e l f r e e t o i n c l u d e a n y c o m m e n t s .
Information supplied by:
Position:
D e p a r t m e n t of P h y s i c s ,
University:
Phone:
Email:
Fax:
THE SURVEY
RESULTS A N D DISCUSSION
Early in t h e Fall of 1 9 9 5 , t h e C A P
survey
was
sent
to
63
physics
d e p a r t m e n t s in c o l l e g e s , CEGEPs a n d
u n i v e r s i t i e s in C a n a d a , i n c l u d i n g all 5 4
CAP member physics departments. The
CAP
survey
that
was
mailed
to
Canadian
academic
institutions
is
s h o w n in T a b l e 1.
A t o t a l of 4 0 r e s p o n s e s t o t h e s u r v e y
w e r e r e c e i v e d in t h e late Fall of 1 9 9 5 ;
2 5 w e r e f r o m PhD g r a n t i n g i n s t i t u t i o n s ,
and
15
from
non-PhD
granting
institutions.
T h e s u r v e y d a t a 1 are
s u m m a r i z e d in T a b l e 2.
No attempt
w a s made to verify numbers that were
p r o v i d e d t o C A P . T h a t is, p e r c e n t a g e s
w e r e tabulated based on the data given
w i t h o u t c h a n g e s or i n t e r p r e t a t i o n (e.g.
n u m b e r s r e p o r t e d by t h e r e s p o n d e n t s
as " a p p r o x i m a t e " w e r e t r e a t e d t h e
s a m e w a y as t h e m o r e " a c c u r a t e "
numbers).
S o m e u n i v e r s i t i e s (2) d i d n o t s u p p l y d a t a f o r B.Sc. g r a d u a t e s . T h e f a c u l t y t o t a l is not equal t o t h e s u m of t e n u r e d f a c u l t y
plus t e n u r e - t r a c k f a c u l t y d u e t o t h e i n c l u s i o n of v i s i t i n g f a c u l t y p o s i t i o n s , f a c u l t y w i t h e m e r i t u s s t a t u s , a n d p a r t - t i m e f a c u l t y
p o s i t i o n s w h i c h r e s p o n d e n t s l i s t e d as f a c u l t y , but n e i t h e r t e n u r e d nor t e n u r e - t r a c k f a c u l t y .
106
Physics in Canada
M arch/Aprill 9 9 6
TABLE 2:
S U M M A R Y OF S U R V E Y R E S U L T S O N W O M E N IN P H Y S I C S IN C A N A D A .
(Received From 40 Canadian Academic institutions
and Collected in the Fail of 1995.)
All Canadian Physics Departments
Total
Number
N u m b e r of
Percentage
Women
Women
(Men & Women)
B.Sc. G r a d u a t e s t
1613
Faculty
707
284
34
Tenured Faculty
Tenure-Track Faculty
621
12
5
2
76
21
28
N u m b e r of
Percentage
Women
Women
18
18
t total number of d e g r e e s granted in t h e period 1 9 9 3 - 1 9 9 5 .
C a n a d i a n PhD G r a n t i n g P h y s i c s D e p a r t m e n t s O n l y
Total
Number
(Men & Women)
B.Sc. G r a d u a t e s t
1453
Ph.D. G r a d u a t e s t
336
261
44
Faculty
Tenured Faculty
612
27
4
539
8
1.5
65
18
28
Tenure-Track Faculty
13
t total number of d e g r e e s granted in the period 1 9 9 3 - 9 5
The
survey
results
show
that
in
C a n a d a , 1 8 % of all r e c i p i e n t s of a B . S c .
D e g r e e in P h y s i c s , a n d 1 3 % of all
r e c i p i e n t s of a Ph.D. D e g r e e in P h y s i c s
are f e m a l e . 5 % of all p h y s i c s f a c u l t y
m e m b e r s a n d 2 % of t e n u r e d p h y s i c s
f a c u l t y m e m b e r s are w o m e n : t h e " l e a k y
p i p e l i n e " t r e n d is p r e s e n t in C a n a d a , in
fact
very
similar t o t h e
situation
o b s e r v e d by our A m e r i c a n c o l l e a g u e s in
their c o u n t r y .
T h e p e r c e n t a g e of w o m e n f a c u l t y at
non-Ph.D.
granting
institutions
is
s o m e w h a t h i g h e r ( 7 % ) t h a n in t h e
Ph.D.
granting
institutions
(4%).
H o w e v e r , it is e n c o u r a g i n g t o see t h a t
a p p r o x i m a t e l y a q u a r t e r of all t e n u r e t r a c k f a c u l t y p o s i t i o n s in t h e p h y s i c s
d e p a r t m e n t s in C a n a d a are c u r r e n t l y
held by w o m e n . It s h o u l d be n o t e d t h a t
t e n u r e - t r a c k f a c u l t y m e m b e r s (of b o t h
g e n d e r ) c o n s t i t u t e o n l y 1 1 % of all
physics faculty members.
In T a b l e 3, r e s u l t s f r o m a s i m i l a r
American survey
[ 2 ] in 1 9 9 4
are
summarized for c o m p a r i s o n w i t h the
C a n a d i a n s u r v e y r e s u l t s p r e s e n t e d in
T a b l e 2.
TABLE 3:
The American
approximately
study.
S U M M A R Y OF R E S U L T S F R O M A N A M E R I C A N S U R V E Y
S I M I L A R T O T H E ONE PRESENTED HERE.
Study provided information
on faculty rank (full, associate, assistant professor),
which is
equivalent to the tenured and non tenured categories presented in Table 2 in this CAP
A m e r i c a n PhD G r a n t i n g P h y s i c s D e p a r t m e n t s O n l y
Total
Number
(Men & Women)
4746
3584
592
Faculty
A s s o c . & Full Prof.
A s s t . Prof.
Number
of W o m e n
Percentage
Women
229
132
60
5
4
10
Data are b a s e d on information in R e f e r e n c e 3.
TABLE 4:
P E R C E N T A G E OF P H Y S I C S D E P A R T M E N T S
W I T H O N L Y O N E OR N O W O M A N F A C U L T Y M E M B E R
N u m b e r of
All Canadian
C a n a d i a n PhD
Canadian non-PhD
American
Women
Faculty
Physics
Departments
Granting Physics
Granting Physics
Departments
PhD G r a n t i n g
Departments*
45%
36%
72%
60%
36%
69%
none
n o n e or o n e
Departments
80%
93%
* Statistics for American P h y s i c s D e p a r t m e n t s are from R e f e r e n c e 3.
T h e s u r v e y r e s u l t s also s h o w e d t h a t of
the
forty
institutions
Canadian
that
academic
responded,
80%
of
w o m a n f a c u l t y m e m b e r in t h e i r p h y s i c s
f a c u l t y m e m b e r s , a v e r y large f r a c t i o n
departments.
of
t h e m h a v e o n e or no w o m a n
faculty
smaller
member,
of
tend
and
almost
a
half
the
r e s p o n d i n g i n s t i t u t i o n s ( 4 5 % ) h a v e no
W h i l e it is t r u e t h a t t h e
non-PhD
to
members,
have
and
granting
fewer
hence
institutions
physics
faculty
fewer
women
them
members
have
no
at all ( 6 0 % )
women
and
faculty
hence
(continued on page 112)
107
W O M E N S T U D E N T S IN P H Y S I C S IN C A N A D A : A D E C A D E OF P R O G R E S S
by
A n n M c M i l l a n , A t m o s p h e r i c Environment Service, 4 9 0 5 D u f f e r i n St., D o w n s v i e w , Ontario, M 3 H 5 T 4
Eric S v e n s s o n , AECL, Chalk River Laboratories, Chalk River, Ontario, KOJ 1 J 0
INTRODUCTION
The C A P collected s o m e data on graduate
s t u d e n t s in u n i v e r s i t y physics as far back
as 1 9 8 3 / 8 4 , f r o m w h i c h it is possible t o
deduce the representation of w o m e n .
Then, a decade ago, the C A P carried out a
s u r v e y of Canadian u n i v e r s i t y physics
d e p a r t m e n t s t o e s t i m a t e the p r o p o r t i o n of
physics s t u d e n t s in Canada w h o w e r e
w o m e n . There w a s little Canadian data
available at that t i m e on p h y s i c s , a l t h o u g h
S t a t i s t i c s Canada had data on engineering
and physical sciences w h i c h could have
included a rather d i f f e r e n t population. The
results of t h a t 1 9 8 5 / 8 6 s u r v e y w e r e
presented at the C A P Congress in 1 9 8 6
and put in c o n t e x t w i t h representation of
w o m e n in h i g h school physics classes and
in the ranks of practicing p h y s i c i s t s . T w o
other C A P s u r v e y s w e r e carried out, one in
1 9 8 6 / 8 7 and one in 1 9 8 8 / 8 9 .
Now, a
decade after the 1 9 8 5 / 8 6 s u r v e y , a n e w
s u r v e y has been carried out in order t o
u p d a t e the n u m b e r s and t o get an
indication of h o w the representation of
w o m e n in physics has changed over the
past decade.
In t h e fall of 1 9 9 5 , a s u r v e y of s t u d e n t s
w a s sent t o Canadian physics d e p a r t m e n t s
in parallel w i t h the s u r v e y of w o m e n
f a c u l t y reported on e l s e w h e r e
in this issue of Physics in
Canada
by
Lagowski
and
McKenna.
The survey sheet
t h a t w a s d i s t r i b u t e d is s h o w n
in Figure 1.
It repeats the
1 9 8 8 / 8 9 s u r v e y and is rather
similar t o the 1 9 8 5 / 8 6 and
1 9 8 6 / 8 7 s u r v e y s in content
and layout, except t h a t it n o w
does not ask for data before
t h i r d year and it does ask for
data at the Post D o c t o r a l level.
TABLE 1
Results of CAP surveys
i»»5/»«
of
responses
?r<*
RESULTS
The
earliest
CAP
data
concerning the representation
of w o m e n in Canadian physics
d e p a r t m e n t s is s u m m a r i z e d in
Table 1 under the c o l u m n for
1 9 8 3 / 8 4 . These numbers are
the result of Mona J e n t o , w h o
w a s the Executive Secretary of
the C A P for m a n y
years,
extracting
the
number
of
women
from
the lists
of
graduate s t u d e n t s s u b m i t t e d t o
the
CAP
[1].
While
31
universities s u b m i t t e d lists, a
number only s h o w e d the initials
of the s t u d e n t s and some did
not break out responses
by degree level. The data
s h o w n w e r e assembled
f r o m 2 4 universities.
i?6»/#?
irnet
24
IS
33
37
38
*
*
*
60
477
537
105
788
893
120
661
781
103
557
660
*
11
12
15
16
*
*
*
45
406
451
93
654
747
107
655
762
130
554
684
*
10
12
14
19
23
357
380
30
310
340
••9
474
533
73
474
547
91
409
500
6
9
11
13
18
11
233
244
24
299
323
25
411
4:16
43
404
447
102
684
786
5
7
6
10
13
*
*
*
*
*
*
*
*
*
9
114
123
24
151
175
*
*
7
14
y*»r
number
number
total
women
4th
n « « / » 7
u n i v y l t y
of
of
women
men
as
% of
total
year
number
number
total
women
of
of
as
women
men
% of
total
MSc
number
number
total
women
of
of
as
women
men
% of
total
PhD
number
number
total
women
Post
of
of
as
women
men
% of
total
DOC
number
number
total
of
of
women
men
women
as
*
available
not
%
of
total
from survey
n U F S T I O N - N A l D F O N W O M F V S T ! " " I F V T S IK PHYSICS
P l r n e return h>
N o v I, 1595
To: F Ford. Executive Director
Cmedian Association o f Physicists
151 Slater Street. #903
Ottawa, Ontario
K1P5H3
University:
Contact Person
Are y o u willing to distribute a
questionnaire to your women students?
Undergraduates
3rd yr.
M. Sc.
Ph.D.
Post D o c
4th yr.
NUMBER
OF:
MALE
FEMALE
The results of the four CAP s u r v e y s
are also s u m m a r i z e d in Table 1. For
these, a request w a s sent t o the
u n i v e r s i t y physics d e p a r t m e n t s t o
c o m p l e t e a f o r m similar t o that
s h o w n in Figure 1. Response rates
increased d r a m a t i c a l l y after the first
survey.
There
were
only
18
responses t o the 1 9 8 5 / 8 6 s u r v e y ,
w h i l e there w e r e 3 3 , 37 and 38
responses,
respectively,
to
the
1986/87,
1988/89
and
1995/96
s u r v e y s , out of 6 3 d e p a r t m e n t s .
M a n y of the later responses included
only the numerical s u m m a r y , but m o s t
u n i v e r s i t y respondents expressed a
willingness t o circulate a questionnaire
t o w o m e n students. A s y e t , w e have
not a t t e m p t e d t o do this.
108
number of women
number of men
total
women as % of total
4th
CAP Survey Form
Physics in Canada
M arch/Aprill 9 9 6
Table 1 includes the t o t a l responses
received
from
all the
surveys.
U n f o r t u n a t e l y , a d i f f e r e n t subset of
universities
responded
to
each
s u r v e y , limiting the c o m p a r a b i l i t y of
the results. It is nonetheless clear
that the representation of w o m e n
students
in Canadian
university
physics d e p a r t m e n t s has increased
over the t i m e period. It is interesting
that in general the number of physics
s t u d e n t s declines w i t h increasing
academic level, w i t h the latest survey
being a marked exception.
58
472
530
74
313
387
11
19
44
403
447
95
362
457
10
21
30
310
340
48
232
280
9
17
24
299
323
5.
)61
419
y—r
number of women
number of men
total
women as 1 of total
sec
number of women
number of men
total
women as % of total
PhD
number of women
number of men
total
women as % of total
N a m e s of female students:
Fig.1
TABLE 2
Results of surveys at 17 universities w h i c h
responded t o b o t h
total number of women
total number of men
grand total
7
14
156
1484
1640
275
1268
154 3
women as % of total
In order t o make
more
meaningful
comparisons, d i f f e r e n t subsets of t h e data
are displayed in Tables 2 - 4 . In Table 2,
the results for the 17 universities that
responded t o b o t h the first and last s u r v e y
are s h o w n .
Note that w h i l e these 17
universities represent only 4 5 % of the
universities that responded in 1 9 9 5 / 9 6 ,
t h e y represent 5 9 % of the t o t a l number of
physics s t u d e n t s .
W h i l e the detailed
university responses are not s h o w n here,
it is interesting t o note t h a t , except at the
M S c level, t h e percentages of w o m e n are
slightly higher in 1 9 9 5 / 9 6 at these 17
universities t h a n at the " n e w
responders",
as indicated by the 1 9 9 5 / 9 6 numbers in
Table 1.
W h i l e the representation of w o m e n has
m a r k e d l y i m p r o v e d , the number of male
s t u d e n t s in physics at these 1 7 universities
has decreased over the last decade, except
at the PhD level. It is not clear w h y the
t h i r d year class in the 1 9 9 5 / 9 6 s u r v e y is
so m u c h smaller than the corresponding
class in 1 9 8 5 / 8 6 . M S c n u m b e r s are also
d o w n at these 17 universities, but PhD
n u m b e r s are up 3 0 % . Is this just the "tail
e n d " of a larger g r o u p t h a t has passed
t h r o u g h or are s t u d e n t s
staying
at
u n i v e r s i t y longer t o finish their PhDs
because of the shortage of jobs and the
e c o n o m i c s i t u a t i o n generally?
last s u r v e y s at these universities, a l t h o u g h
not
so
substantially
at
these
25
universities as at the 17 covered by Table
2. The n u m b e r of w o m e n at each level
also increased over the period, a l t h o u g h
the number of m e n decreased at every
level e x c e p t PhD, and fell 1 0 % overall.
The t o t a l number of physics s t u d e n t s has
remained relatively c o n s t a n t for these
universities, but their d i s t r i b u t i o n a m o n g
the academic levels has changed m a r k e d l y ,
w i t h the number of PhD s t u d e n t s up 5 6 %
in this sample of universities. Tables 1,2
and 3 all indicate that the number of
w o m e n in third year at the present time
( 1 9 9 5 / 9 6 ) , and their representation, is
slightly less t h a n in f o u r t h year. This could
be the beginning of a reversal in the trend
t o increased representation.
Future
s u r v e y s should help t o c l a r i f y this point.
TABLE 3
Results of surveys at 25 universities
lM«/»7
3rd
women a s % of
4th
1988/89
1995/96
Y«r
number of w o m e n
number of men
total
total
75
581
656
68
474
542
85
477
562
11
13
15
77
521
598
61
403
464
89
362
451
13
13
20
54
396
450
62
388
450
72
319
391
22
350
372
33
390
423
76
504
580
y«»r
number of women
number of men
total
w o m e n a s % of
total
MSC
number of women
number of m e n
total
women as % of
total
number of w o m e n
number of m e n
total
women a s % of
total
total n u m b e r of women
total number of m e n
grand t o t a l
w o m e n a s * of
total
6
8
13
228
1848
2076
224
1655
1879
322
1662
1984
11
12
16
TABLE 4
Results f r o m 2 0 universities submitting data for both
1 9 8 3 / 8 4 and 1 9 9 5 / 9 6
1983/84
number of women
number of men
total
women as a % of total
msai
20
297
317
64
276
340
6
PhD
number of women
number of men
total
women as a % of total
11
218
229
5
Table 3 s h o w s the results for
the
universities t h a t responded t o the later
s u r v e y s . There w e r e 1 7 universities w h i c h
responded t o each of the
1986/87,
1988/89
and
1995/96
surveys
and
another 8 t h a t responded t o b o t h the
1 9 8 6 / 8 7 and 1 9 9 5 / 9 6 s u r v e y s . For these
8 universities, linear interpolation w a s
arbitrarily
used to estimate
n u m b e r s for
1988/89.
Table 3 s h o w s that the
representation of w o m e n in physics has
definitely increased b e t w e e n the first and
66
458
524
Table 4 s h o w s results for
the
20
universities
s u b m i t t i n g data for b o t h
1 9 8 3 / 8 4 and 1 9 9 5 / 9 6 .
The
percentages
of
women
in
graduate
schools
have
nearly
tripled over this period at
these universities. The
t o t a l number of PhD
s t u d e n t s has more t h a n
doubled,
while
the
number
of
Masters
s t u d e n t s has increased
less than 1 0 % .
Note
that the actual number of
w o m e n at the PhD level
as s h o w n in this sample
has gone up a f a c t o r of
6.
DISCUSSION A N D
CONCLUSIONS
The CAP survey data
indicates several t h i n g s :
t h a t the representation
of w o m e n s t u d e n t s in
Canadian
university
physics d e p a r t m e n t s has
increased
substantially
over
the
period
surveyed,
that
the
number
of
women
physics
students
in
Canada has increased
substantially and that
the
representation
of
women
university
physics
students
still
decreases
with
increasing
academic
level.
Tables 1, 2, 3 and 4 all
indicate that the representation of w o m e n
s t u d e n t s has increased. The size of the
increase varies s o m e w h a t w i t h the data
sets used. It is m o s t striking t h a t , at the
PhD level, representation has essentially
doubled over the last decade.
These results can be put into c o n t e x t w i t h
those g i v e n by Statistics Canada in
" W o m e n in Canada: A Statistical Report"
[ 2 | . Table 5, f r o m t h i s report, gives data
for full t i m e enrolment by field of s t u d y for
<H—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—r75
77
79
B1
83
85
67
B9
91
Academic Year
Sourc«: U.S. D«partm«nt of Education
Fig. 2
Percent of Bachelors Degrees in
Selected Fields Earned by W o m e n ,
1975 to 1992.
50
0^—i
n
1 1 1 1 1 1 1 1 1—i 1 1 1—r
80
82
84
88
88
80
32
Year Degree G - a i l e d
(Source: NfiC Summary Report, verloue yeare. The data dted tor phyalce PhDe earned
ere trom the AiP Enrollment» end Degree» Reporte " * )
Fig. 3
Percent of PhD's Earned by W o m e n in
Selected Fields, 1 9 7 8
1993.
1 9 7 2 - 7 3 , 1 9 8 1 - 8 2 and 1 9 9 2 - 9 3 . The
numbers g i v e n for engineering/applied
sciences in 1 9 8 1 / 8 2 and 1 9 9 2 / 9 3 are
similar t o those s h o w n in our Tables and,
in f a c t , agree w i t h the overall percentages
s h o w n in the last line of Table 2 for
1 9 8 5 / 8 6 ( 1 0 % ) and 1 9 9 5 / 9 6 ( 1 8 % ) .
Figure 2 131 s h o w s the representation of
w o m e n in the U . S . A . obtaining bachelors
degrees in selected fields. In p h y s i c s , the
percentage of bachelors degrees a w a r d e d
in the U . S . A . has risen f r o m about 1 0 % in
1 9 7 5 t o about 1 6 % in 1 9 9 2 .
If w e
c o m p a r e these figures w i t h those f r o m our
survey for the f o u r t h year and M S c levels,
w e see t h a t the increase in representation
109
Table
6
also
s h o w s t h a t the
r e p r e s e n t a t i o n of
1992-93
1981-82
1972-73
women
in
all
Women
Women
Women
as a % of
as a % ot
as a % of
fields d r o p s f r o m
total in
total In
total in
53.4%
at
the
%
field
field
OOQs
%
field
- 000s
000s
%
bachelors degree
Field i l study
level t o 3 5 . 2 % at
66.5
13.8
Education
33.4
21.2
56.2
45.0
18.4
67.0
40.4
t h e PhD
level.
These S t a t i s t i c s
61.8
3.8
Fine/applied arts
5.9
3.8
59.9
10.8
4.4
63.6
11.2
Canada
figures
12.6
59.8
48.1
23.5
9.6
58.8
36.7
Humanities
19.4
12.3
indicate t h a t , in
32,4
53.5
28.9
66.4
27,2
44.8
94.5
Social sciences
24,4
15.4
1992/93, women
Agricultural/biological
made u p m o r e
7.3
56.8
sciences
8.9
5.6
40.4
12.5
5.1
52.2
21.2
than
half
the
Engineering/applied
3.4
18.0
sciences
0.7
0.4
2.7
4.7
1.9
10.4
9.8
u n i v e r s i t y
656
e n r o l m e n t at the
Health professions
10.3
6.5
7.3
51.2
17.0
7.0
63.1
21.2
underg raduate
Mathematics/physical
28.4
sciences
4.1
2.6
19.1
8.2
3.3
26.3
9.8
3.3
level
in
every
40.4
244.1
100.0
48.6
292.0
52.2
Total'
157.7
100.0
100 0
field
except
enginoering/appli
ed sciences and
mathematics/ph
y s i c a l sciences.
Even
at
the
Table 6
PhD
l e v e l ,
Women as a percentage ol full-time university enrolment, by level and tield ot study. 1992-93
Bachelor's
w o m e n is at least
and first
professional
33%
in
every
degree
Master's
Doctorate
Total
field e x c e p t these
two.
Figures 2
Field of study
and 3 for t h e
Education
66 8
65.8
60.0
66.5
U.S.A.
indicate
Fine/applied arts
62 2
61 8
58.8
45.5
Humanities
61,2
45.7
59,8
55,8
t h a t
t h e
Social sciences
54 4
44.7
46.6
53.5
59.0
Agriculture/biological sciences
49.6
33.2
56.8
Engineering/applied sciences
18.5
18.2
10.6
18,0
women
at
the
Health professions
67.7
43.4
62.0
65.6
Mathematics/physical sciences
27.1
18.6
28.4
29.9
bachelors degree
Total'
53.4
46.2
52.2
35.2
level overall w a s
about
54%
in
1 9 9 2 w h i l e at the
PhD level it w a s about 3 7 % . Engineering
and p h y s i c s are the t w o areas in w h i c h
Figure 4 |4J, based o n A m e r i c a n I n s t i t u t e
representation is the l o w e s t .
of Physics (AIP) data for the U . S . A . o f f e r s
a possible e x p l a n a t i o n . In the U . S . A . , the
n u m b e r of physics PhD's is e x p e c t e d t o
peak b e t w e e n 1 9 9 4 and 1 9 9 8 and t h e n t o
decline rather d r a m a t i c a l l y t o levels about
t h e s a m e as those a decade earlier. If the
These results indicate t h a t , in the u n i v e r s i t y
s i t u a t i o n in Canada is similar, it w o u l d
c o m m u n i t y as a w h o l e , r e p r e s e n t a t i o n of
e x p l a i n the large number of p h y s i c s PhD
w o m e n at the undergraduate level is no
s t u d e n t s reported in our 1 9 9 5 / 9 6 s u r v e y .
longer a serious c o n c e r n . H o w e v e r , t h e
This e x p l a n a t i o n is also r e i n f o r c e d by the
science-based
professions,
particularly
n u m b e r s in third year in our 1 9 9 5 / 9 6
p h y s i c s and engineering, c o n t i n u e to have
s u r v e y . For s o m e universities (Tables 1
a problem a t t r a c t i n g w o m e n s t u d e n t s and
and 2), t h e third year class is smaller t h a n
the loss of partially trained w o m e n s t u d e n t s
the f o u r t h year class.
The number of
is a p r o b l e m in the u n i v e r s i t y c o m m u n i t y for
w o m e n s t u d e n t s is also l o w e r , as is their
all disciplines.
representation.
Further s u r v e y s w i l l be
required t o e s t a b l i s h w h e t h e r or not this
apparent change in trend is real.
Tabla 5
Full-time university enrolment ot women by Held ol study, 1972-73, 1981-82 and 1992-93
1500
1400
I
1300
1200
IIl l
1100
1
1000
1
900
iN
800
700
III
600
1963
1905
1987
1969
1991
1993
1995
1997
1999
2301
Year
Projected Number of Degrees, 1 9 9 5 - 2 0 0 1
Source: A I P Education and Employment Statistics Division
Fig. 4 .
Thedarkbarsindicateactual physics PhD
p r o d u c t i o n b e t w e e n l 9 8 3 and 1 9 9 4 . T h e
t w o - t o n e bars indicate high and l o w
estimates for projected PhD production.
appears m o r e rapid in Canada. Our results
f r o m 1 9 8 5 / 8 6 in Table 2 i m p l y t h a t about
1 0 % of t h e bachelors degrees in p h y s i c s
w e r e a w a r d e d t o w o m e n and t h a t , by
1995/96,
t h e n u m b e r had essentially
doubled.
Figure 3 131 s h o w s t h e r e p r e s e n t a t i o n of
w o m e n in t h e U . S . A . obtaining P h D ' s in
selected fields.
The r e p r e s e n t a t i o n in
p h y s i c s has risen f r o m about 5 % in 1 9 7 8 t o
about 1 2 % in 1 9 9 3 . These figures are v e r y
c o n s i s t e n t w i t h , for e x a m p l e , the 5 % in
1 9 8 3 / 8 4 and the 1 3 % in 1 9 9 5 / 9 6 s h o w n in
our Tables 1 and 4 .
Hence, although
representationappearstobeincreasingmore
rapidly in Canada t h a n in t h e U . S . A . at t h e
b a c h e l o r s l e v e l , the i n c r e a s e in
r e p r e s e n t a t i o n at the PhD level s e e m s about
the s a m e in t h e t w o c o u n t r i e s .
Tables 1, 2, 3 and 4 s h o w that not only
t h e r e p r e s e n t a t i o n , but also the n u m b e r of
w o m e n u n i v e r s i t y p h y s i c s s t u d e n t s has
increased in Canada. T h i s increase is m o s t
d r a m a t i c at t h e PhD level.
It is still
sobering t o reflect on the v e r y small actual
n u m b e r of w o m e n p h y s i c i s t s at that level.
It is clear t h a t t o change t h e overall
representation
in
the
Canadian
professional p h y s i c s c o m m u n i t y w i l l t a k e
a v e r y long t i m e .
In general, f o r m o s t of our s u r v e y s , the
n u m b e r of w o m e n s t u d e n t s d r o p s off w i t h
increasing a c a d e m i c level, as does t h e
t o t a l n u m b e r of s t u d e n t s .
This is not
universally
true,
however,
and
the
1 9 9 5 / 9 6 s u r v e y results are d i f f e r e n t in this
regard.
In
the
1995/96
survey,
summarized
for
different
groups
of
u n i v e r s i t i e s in Tables 1, 2, 3 and 4 , t h e
n u m b e r of w o m e n PhD s t u d e n t s is greater
t h a n the n u m b e r of w o m e n M S c s t u d e n t s .
F u r t h e r m o r e , t h e n u m b e r of male PhD
s t u d e n t s and hence the t o t a l n u m b e r of
PhD s t u d e n t s are also greater t h a n t h e
c o r r e s p o n d i n g n u m b e r s at t h e M S c level.
110
Physics in Canada
M arch/Aprill 9 9 6
The data s h o w n in Tables 1, 2, 3 and 4
indicates that in all years except 1 9 9 5 / 9 6
the r e p r e s e n t a t i o n of w o m e n falls off w i t h
increasing academic level, t y p i c a l l y by
about 4 - 5 % (out of 1 1 - 1 9 % ) f r o m third
year to PhD level. Table 6 | 2 | s h o w s that
the
representation
of
women
in
engineering/applied sciences in 1 9 9 2 / 9 3
fell f r o m 1 8 . 5 % (bachelors) to 1 0 . 6 %
(PhD) a c c o r d i n g t o S t a t i s t i c s Canada.
Figures 2 and 3 indicate t h a t
the
representation
of
women
physics
g r a d u a t e s in the U . S . A . in 1 9 9 2 w a s about
1 6 % at the bachelors degree level and
about 1 1 % at the PhD level.
This decrease in t h e r e p r e s e n t a t i o n of
w o m e n w i t h m o r e a d v a n c e d academic level
is a p h e n o m e n o n not l i m i t e d t o p h y s i c s .
A l t h o u g h w o m e n are n o w
equitably
represented in u n i v e r s i t y e d u c a t i o n in
Canada, and their representation in p h y s i c s
has a l m o s t d o u b l e d over t h e past d e c a d e ,
p h y s i c s still remains one of the areas w h e r e
representation of w o m e n is poorest.
In
addition, w o m e n still d r o p out of p h y s i c s
e d u c a t i o n relatively more f r e q u e n t l y t h a n
m e n do.
Current
physics
student
d e m o g r a p h i c s leads one t o e x p e c t t h a t ,
over at least t h e next several y e a r s , t h e
r e p r e s e n t a t i o n of w o m e n a m o n g the n e w
hires in Canadian p h y s i c s positions, and
hence
among
the
total
Canadian
professional p h y s i c i s t
population,
will
exhibit a s l o w increase. It w i l l , h o w e v e r , be
several decades, if ever, before there is an
( c o n t i n u e d on page 113)
W E S - W O M E N IN E N G I N E E R I N G A N D S C I E N C E : A C A N A D I A N S U C C E S S S T O R Y A T N R C
by
Marie D ' l o r i o , Institute for M i c r o s t r u c t u r a l Sciences, National Research Council of Canada, O t t a w a , Ontario K 1 A 0 R 6
In N o v e m b e r 1 9 9 0 , the National Research
Council (NRC) launched a W o m e n in
Engineering and Science program in its
laboratories t o encourage the participation
of Canadian w o m e n in the science and
engineering professions. Each year since
1 9 9 1 , t w e n t y - f i v e o u t s t a n d i n g first year
female s t u d e n t s enrolled in a Canadian
U n i v e r s i t y or in a final year of CEGEP have
been selected
f r o m across Canada t o
w o r k for three s u m m e r s or co-op t e r m s in
NRC
laboratories
while
studying
in
scientific or engineering disciplines in
w h i c h w o m e n are t r a d i t i o n a l l y underrepresented. The student is paired w i t h a
NRC scientist w h o acts as a m e n t o r t o link
the academic training, w o r k a s s i g n m e n t s
and career aspirations of the s t u d e n t . In
particular, the m e n t o r helps identify a
project suited t o the s t u d e n t ' s interest
and provides guidance w h e n needed. The
s t u d e n t s are encouraged to experience
different
research
environments
and
supervisors, although s o m e prefer t o
" g r o w " w i t h i n a research g r o u p for the
three w o r k t e r m s .
The s t u d e n t s a c c e p t e d into the Program
are e x p e c t e d t o serve as role models for
other w o m e n c o n t e m p l a t i n g careers in
science
and
engineering
and
must
represent the National Research Council
w h e n the o p p o r t u n i t y presents itself. T w o
g r o u p s of W E S s t u d e n t s have
now
c o m p l e t e d the Program and more t h a n
85%
of these have registered
into
graduate school or are pursuing careers in
science and engineering. Criteria for
selection of W E S participants include:
academic
interests
and
performance,
extracurricular
pursuits,
employment
h i s t o r y , initiative, c o m m u n i t y i n v o l v e m e n t
and c o m m u n i c a t i o n skills. Each u n i v e r s i t y
can r e c o m m e n d up to three s t u d e n t s .
Elke A i p p e r s b a c h f r o m the U n i v e r s i t y of
Alberta spent three s u m m e r s in J e n n y
Phipps' laboratory in the Institute for
Biological
Sciences
(IBS),
Tissue
Regeneration and Transgenics
Group.
During her second w o r k t e r m at NRC, Elke
c o m m e n t e d : " I n a lab like this t h e r e ' s so
m u c h t o get i n v o l v e d w i t h . This year, I
w o r k e d on the e f f e c t of a peptide of
hormonal origin on the cellular cycle. Last
year, I w a s i n v o l v e d in a collaborative
SIMS (Steacie Institute for Molecular
Sciences) and IBS project s t u d y i n g a
possible t r e a t m e n t of c a n c e r " * . A s she
headed t o w a r d s pursuing graduate degrees
in B i o c h e m i s t r y at the U n i v e r s i t y of
T o r o n t o , Elke had a g o o d idea of w h a t a
professional researcher's career entailed.
She added: " I n school, y o u get an idyllic
v i e w of research. If y o u r e x p e r i m e n t
d o e s n ' t w o r k , y o u still k n o w the results
y o u w e r e supposed t o get. At NRC, y o u
d o n ' t a l w a y s get the results y o u ' r e looking
f o r , but y o u have t o learn t o be open t o
w h a t y o u r failures can t e a c h y o u . " Her
m e n t o r ' s perspective on interacting w i t h
s t u d e n t s w a s : " T h e y ask questions that
w e have f o r g o t t e n t o ask s o m e w h e r e
along the w a y " . J e n n y Phipps w a s busy
a n s w e r i n g questions and guiding the
research of four s t u d e n t s w o r k i n g w i t h her
t h a t s u m m e r . Since 1 9 9 1 , preference has
been extended t o candidates in fields in
which
women
are
underrepresented:
m a t h e m a t i c s , p h y s i c s , and engineering.
The s t u d e n t s w h o w e r e c h o s e n for this
year's
program w e r e invited t o
an
orientation session at NRC in A u g u s t .
There, t h e y met prospective m e n t o r s ,
learned about the research projects in
various Institutes, and talked t o other WES
s t u d e n t s in their first, second and third
year in the Program. The W E S participants
have established an e f f e c t i v e n e t w o r k of
i n f o r m a t i o n and activities providing the
m u t u a l support w h i c h o f t e n drives first
class s t u d e n t s t o surpass excellence.
Sheri Lynn Lewis w i t h Dr. S. Elgazzar, Institute
for Information T e c h n o l o g y / I n s t i t u t
de
technologic de l'information, O t t a w a .
projet et de directeur de recherche bien
Those of us w h o have served as m e n t o r s
hope that the W E S Program w i l l continue t o
enrich our personal and professional lives for
years to c o m e ! I n f o r m a t i o n about this
program is available t h r o u g h the u n i v e r s i t y
a w a r d s o f f i c e and t h r o u g h NRC at the
f o l l o w i n g address:
Carole Greffe
National Research Council of Canada
H u m a n Resources Branch
Recruitment O f f i c e
O t t a w a , Ontario K 1 A 0 R 6
Tel: (613) 9 9 3 - 3 5 4 3
F A X : (613) 9 9 0 - 7 6 6 9
* Sphere, M a y 1 9 9 4
Karla Randell w i t h Dr. J. Balsevich, Plant
Biotechnology Institute/lnstitut de technologie
des plantes. Saskatoon.
P I C - P R O G R A M M E D ' I N G E N I E U R E S ET C H E R C H E U S E S :
U N P R O G R A M M E C A N A D I E N C O U R O N N É DE S U C C È S
AU CNRC
par
Marie D ' l o r i o , Institut des sciences des m i c r o s t r u c t u r e s ,
Conseil national de recherches du Canada, O t t a w a , Ontario K l A 0 R 6
En n o v e m b r e 1 9 9 0 , le Conseil national de
recherches du Canada (C NRC) a mis sur pied
un p r o g r a m m e d ' i n g é n i e u r e s et chercheuses
(PIC) visant à encourager les Canadiennes à
poursuivre des études en sciences et en
génie. Chaque année depuis 1 9 9 1 , le CNRC
a invité v i n g t - c i n q étudiantes très douées,
venant des quatre c o i n s d u pays, à travailler
dans ses laboratoires pendant trois étés ou
s e m e s t r e s c o - o p t o u t en poursuivant des
études dans des disciplines où les f e m m e s
sont traditionnellement sous-représentées.
Les étudiantes d o i v e n t avoir t e r m i n é une
première année d ' u n p r o g r a m m e de premier
cycle dans une université canadienne ou un
n i v e a u é q u i v a l e n t au
Québec.
L'apprentissage de ces étudiantes est
f a c i l i t é par le j u m e l a g e de c h a q u e
participante à un scientifique du CNRC dont
le rôle de conseiller consiste à aider
l ' é t u d i a n t e t o u t au long des trois années du
p r o g r a m m e , de la guider dans le choix de
projets de recherche, de la conseiller quant
à l ' o r i e n t a t i o n de sa carrière et d ' ê t r e
disponible pour discuter de ce qui a trait aux
o b j e c t i f s du p r o g r a m m e de f o r m a t i o n et aux
affectations.
Les é t u d i a n t e s
sont
encouragées à diversifier leurs choix de
que certaines préfèrent un apprentissage au
sein d ' u n m ê m e groupe de recherche
pendant trois ans. Les étudiantes admises
au p r o g r a m m e d o i v e n t servir de modèles à
d ' a u t r e s f e m m e s qui envisagent de faire
carrière en sciences ou en génie et d o i v e n t
représenter, si nécessaire, le Conseil
national de recherches dans le cadre de
salons de l ' e m p l o i et journées d ' o r i e n t a t i o n
sur les c a m p u s universitaires. Deux groupes
d ' é t u d i a n t e s ont c o m p l é t é leur apprentissage au sein du p r o g r a m m e et plus de
8 5 % de ces diplômées poursuivent des
études de d e u x i è m e et t r o i s i è m e cycle ou se
sont engagées dans des carrières en
sciences et en génie. Parmi les critères de
sélection pour les participantes du PIC, on
c o m p t e les intérêts sur le plan académique
et parascolaire, l'esprit d ' i n i t i a t i v e , les
a c t i v i t é s c o m m u n a u t a i r e s , la c o m m u n i cation orale et les expériences de travail.
Chaque université peut poser la candidature
de trois étudiantes.
Elke A i p p e r s b a c h
de
l'université
de
l ' A l b e r t a a oeuvré pendant trois étés
dans le laboratoire de J e n n y Phipps de
l ' I n s t i t u t des sciences biologiques (ISB),
111
groupe de regénération tissulaire et de
recherche transgénique. A u cours de s o n
t r o i s i è m e été au CNRC, Elke a parlé de sa
recherche en ces t e r m e s * : " D a n s un labo
c o m m e celui-ci, il y a de nombreux projets
auxquels vous avez la chance de participer.
C e t t e année, j ' a i étudié l ' e f f e t d ' o r i g i n e
hormonale sur le c y c l e de la cellule. L ' a n
dernier, j ' a i participé à un d ' u n peptide
projet en collaboration avec l ' I n s t i t u t
Steacie des sciences moléculaires sur un
t r a i t e m e n t possible du c a n c e r . " A l o r s
q u ' e l l e s ' a p p r ê t a i t à c o m m e n c e r une
Maîtrise en biochimie à l ' u n i v e r s i t é de
T o r o n t o , Elke avait déjà une idée assez
précise de ce que serait sa carrière de
chercheuse. Elle ajouta: " À l ' u n i v e r s i t é , on
v o u s présente une v i s i o n idéalisée de la
recherche. Si v o t r e expérience ne marche
pas, v o u s savez au moins quels auraient dû
être les résultats. A u CNRC, il arrive que
vous
n'obteniez
pas
les
résultats
recherchés, mais on s ' a t t e n d à ce que
v o u s appreniez aussi de v o s é c h e c s . "
Selon sa conseillère, J e n n y Phipps, "le fait
de travailler avec des é t u d i a n t s nous f o r c e
à être plus vigilants. Ils nous posent des
questions que, parfois, nous avons oublié
de nous poser en cours de r o u t e . " J e n n y
Phipps était bien placée pour parler
puisqu'elle supervisait les t r a v a u x de
quatre adjoints d ' é t é dont Elke. Depuis
1 9 9 1 , la préférence est accordée aux
étudiantes inscrites dans des domaines où
les f e m m e s sont sous-représentées soit les
m a t h é m a t i q u e s , la physique et le génie.
Les étudiantes qui ont été choisies pour le
c o n c o u r s de 1 9 9 5 ont été invitées à une
journée d ' o r i e n t a t i o n au CNRC au mois
d ' a o û t . Elles ont rencontré des conseillers
et conseillères, ont eu un bref aperçu des
projets de recherche de divers I n s t i t u t s et
ont
pu
rencontrer
des
étudiantes
participant au p r o g r a m m e des ingénieures
et chercheuses depuis un, deux et trois
ans. Les participantes du PIC ont mis sur
pied un réseau d ' i n f o r m a t i o n et organisé
des a c t i v i t é s qui les épaulent durant leur
séjour au CNRC leur p e r m e t t a n t d'aller audelà de l'excellence.
Pour ceux et celles parmi nous qui ont eu
le plaisir d ' ê t r e conseiller et conseillère, il
ne reste plus q u ' à espérer que le
p r o g r a m m e d ' i n g é n i e u r e s et chercheuses
continuera d ' e n r i c h i r notre vie personnelle
et professionnelle pendant les années à
venir! Pour de plus amples i n f o r m a t i o n s sur
ce
programme
du
CNRC,
veuillez
c o m m u n i q u e r avec le service des bourses
de v o t r e u n i v e r s i t é ou avec le CNRC à
l'adresse suivante:
Carole G r e f f e
C o n s e i l n a t i o n a l de r e c h e r c h e s d u C a n a d a
Direction des ressources humaines
G r o u p e de r e c r u t e m e n t
Ottawa, Ontario K1A 0R6
Tél: (613) 9 9 3 - 3 5 4 3
FAX: (613) 9 9 0 - 7 6 6 9
* Sphère, mai 1 9 9 4
Women
Physics
Faculty
J.
Lagowski
and
J.
...
by
McKenna
have
no
role m o d e l s f o r
undergraduate w o m e n students.
their
In T a b l e 4 t h e s e C a n a d i a n s t a t i s t i c s are
compared w i t h the analogous statistics
in t h e U n i t e d S t a t e s of A m e r i c a f o r
1994.(3)
T h e s i t u a t i o n in Canada is
indeed v e r y s i m i l a r t o t h a t in A m e r i c a n
universities.
CONCLUSIONS
T h i s a r t i c l e s h o u l d not be t a k e n as a
definitive
study
(see
for
example
f o o t n o t e 1, also no a t t e m p t w a s m a d e t o
e s t i m a t e t h e a c c u r a c y of f i n a l n u m b e r s )
o n w o m e n in p h y s i c s in C a n a d a .
The
r e s u l t s of t h i s s u r v e y s u g g e s t t h a t
f u r t h e r s t u d i e s c o u l d be u n d e r t a k e n in
o r d e r t o a d d r e s s q u e s t i o n s s u c h as: (1)
W h a t w a s t h e e f f e c t of W o m e n ' s F a c u l t y
A w a r d s ( W F A ) (a p r o g r a m s p o n s o r e d by
the Natural Sciences and Engineering
Research
Council)
on
the
above
p e r c e n t a g e s ? (2) Do w o m e n p r o g r e s s t o
t e n u r e m o r e s l o w l y t h a n m e n ? (3) H o w
w o u l d t h e i n c l u s i o n of i n s t i t u t i o n s t h a t
chose not to reply to the survey affect
t h e a b o v e r e s u l t s ? and p o s s i b l y o t h e r
q u e s t i o n s t h a t w o u l d i n d i c a t e w a y s of
a s s e s s i n g and i m p r o v i n g t h e s i t u a t i o n f o r
female
physicists
in t h e
Canadian
institutions.
W e c o n c l u d e by s t a t i n g
t h a t w i t h 5 % r e p r e s e n t a t i o n of w o m e n
in p h y s i c s d e p a r t m e n t s at t h e f a c u l t y
l e v e l , t h e s i t u a t i o n f o r w o m e n in p h y s i c s
in C a n a d a is c o m p a r a b l e t o t h a t in t h e
U n i t e d S t a t e s of A m e r i c a , and n o t a b l y
w o r s e t h a n t h a t of m a n y E u r o p e a n
countries.
REFERENCES
( 1 ) W . J . M e g a w , " G e n d e r D i s t r i b u t i o n in
the W o r l d ' s Physics D e p a r t m e n t s " ,
paper p r e p a r e d f o r t h e m e e t i n g ,
G e n d e r and S c i e n c e and T e c h n o l o g y
6, Melbourne, Australia, July 14-18,
1991.
(2)
M i l d r e d S. D r e s s e l h a u s , " U p d a t e o n
t h e C h i l l y C l i m a t e f o r W o m e n in
P h y s i c s , " C o m m i t t e e o n S t a t u s of
W o m e n in P h y s i c s G a z e t t e , V o l . 1 4 ,
N o . 1, S p r i n g 1 9 9 4 .
M i l d r e d S. D r e s s e l h a u s , J u d y Franz,
B u n n y C. C l a r k , " I m p r o v i n g t h e
Climate for W o m e n
in
Physics
Departments",
p u b l i s h e d by t h e
A m e r i c a n P h y s i c a l S o c i e t y and t h e
A m e r i c a n A s s o c i a t i o n of P h y s i c s
Teachers.
(3) A m e r i c a n
Institute
of
Physics;
Education,
Employment
and
S t a t i s t i c s D i v i s i o n , d a t a f o r t h e year
1994.
The movement for active, healthy living
112
Physics in Canada
M arch/Aprill 9 9 6
T H E C O M M I T T E E O N T H E S T A T U S O F W O M E N IN P H Y S I C S O F T H E A M E R I C A N P H Y S I C A L
SOCIETY
by
Luz M a r t i n e z - M i r a n d a
The C o m m i t t e e on the Status of W o m e n in
Physics of t h e A m e r i c a n Physical Society
(CSWP) w a s chartered in 1 9 7 2 . Over the
years, the C o m m i t t e e has sponsored
activities aimed b o t h at increasing the
participation and representation of w o m e n
in Physics and related fields.
The C S W P has nine m e m b e r s appointed t o
three year t e r m s by the APS. C u r r e n t l y ,
the
CSWP
is
organizing
three
s u b c o m m i t t e e s : Education, Industry and
International,
to
better
enable
the
c o m m i t t e e t o take advantage of the m a n y
eager v o l u n t e e r s w h o w i s h t o c o n t r i b u t e t o
the c o m m i t t e e ' s projects.
For more i n f o r m a t i o n on C S W P p r o g r a m s ,
please c o n t a c t Tara M c L o u g h l i n at APS
headquarters (301) 2 0 9 - 3 2 3 1 or e-mail
tara@aps.org.
Some of the activities the C S W P sponsors
are:
1. a Roster of W o m e n in Physics;
2. W o m e n in Physics (WIPHYS), a
m o d e r a t e d internet f o r u m ;
3. a c o l l o q u i m / s e m i n a r s p e a k e r ' s list;
4. travel g r a n t s for w o m e n speakers;
5. Physics D e p a r t m e n t Site Visit Program.
In addition, C S W P publishes The Gazette,
a q u a r t e r l y n e w s p a p e r , and sponsors
s y m p o s i a , receptions and presentations at
the general and divisional meetings of the
A m e r i c a n Physical S o c i e t y . M o s t recently,
C S W P has sponsored a breakfast m e e t i n g
of w o m e n in i n d u s t r y , j o i n t l y w i t h the
C o m m i t t e e on the A p p l i c a t i o n s of Physics.
These p r o g r a m s are described in the
following.
ROSTER OF W O M E N IN PHYSICS
The Roster of W o m e n in Physics is a
database c o n t a i n i n g the names, addresses
and fields of expertise of w o m e n in
physics at all levels f r o m student t o
professional.
Academic
institutions,
g o v e r n m e n t and industrial laboratories
interested in reaching a pool of potential
j o b applicants in a specific field can
c o n t a c t APS and request a search of the
database.
APS
will
mail
job
a n n o u n c e m e n t s and pertinent i n f o r m a t i o n
t o candidates w h o s e q u a l i f i c a t i o n s m a t c h
the i n s t i t u t i o n s ' specified requirements.
The i n f o r m a t i o n contained in the Roster is
confidential and therefore the list is not
available for d i s t r i b u t i o n .
A
Roster
application f o r m appears in every issue of
The Gazette.
W O M E N IN PHYSICS (WIPHYS)
W I P H Y S is a m o d e r a t e d Internet f o r u m for
the discussion of issues related t o w o m e n
in p h y s i c s . This electronic f o r u m o f f e r s
unique possibilities t o assist in creating an
a t m o s p h e r e of cooperation, m e n t o r i n g and
support in a field w h e r e w o m e n are a
m i n o r i t y , and t h u s o f t e n feel isolated.
WIPHYS
was
"officially"
started
in
J a n u a r y , 1 9 9 3 , and n o w has over
subscribers.
600
Examples of discussions on W I P H Y S :
- a n n o u n c e m e n t of g o v e r n m e n t or privately
sponsored programs designed to aid in
establishing the careers of
women
scientists;
- postings of j o b listings;
- n e w s about w o m e n in physics;
- on-line
mentorship
(issues
recently
discussed include sexual h a r a s s m e n t , the
impact of changing o n e ' s name on
publications and research, advice on the
tenure process);
- i n f o r m a t i o n on w o m e n ' s e v e n t s at APS
m e e t i n g s (postings on informal and
planned dinners, receptions, sessions,
help for those seeking r o o m m a t e s ) ;
- advice on teaching (suggestions for
textbooks,
discussion
of
different
learning styles).
In order t o subscribe to W I P H Y S , send an
e-mail message to: l i s t s e r v @ a p s . o r g
The subject line should be blank, and the
text
of
the
message
should
read:
subscribe w i p h y s
C O L L O Q U I M A N D SEMINAR SPEAKER'S
LIST OF W O M E N IN PHYSICS
The Colloquim and Seminar Speaker's list
of W o m e n in Physics is published every
year and d i s t r i b u t e d
t o all
Physics
D e p a r t m e n t Heads in the U . S . A . and
others by request. This booklet contains
the names of w o m e n speakers and seminar
titles arranged by field, geographical area
and presentation level (general audiences,
high school audiences, technical seminar).
The
list serves as a resource
for
d e p a r t m e n t s interested in inviting w o m e n
speakers to their seminar series.
and the A m e r i c a n A s s o c i a t i o n of Physics
Teachers (AAPT). Funded by the National
Science Foundation and the APS, this
program w a s aimed at d e t e r m i n i n g w h i c h
f a c t o r s a f f e c t the retention and success of
w o m e n in Physics D e p a r t m e n t s at all levels
(undergraduate, graduate and f a c u l t y ) at
research universities in the U . S . A . The final
report on this p r o g r a m , w r i t t e n by Profs.
Mildred Dresselhaus, (MIT); J u d y Franz,
Executive O f f i c e r of the APS, U n i v e r s i t y of
A l a b a m a ; and Bunny Clark, Ohio State
U n i v e r s i t y , is available f r o m APS by
c o n t a c t i n g Erika R i d g e w a y at (301) 2 0 9 3269.
This report details
specific
r e c o m m e n d a t i o n s t o i m p r o v e the c l i m a t e
for w o m e n in Physics D e p a r t m e n t s .
As
the report points o u t , many of these
r e c o m m e n d a t i o n s , including the availability
of safe undergraduate s t u d y
rooms,
recruitment
of
women
faculty,
and
guidance for those c o m b i n i n g w o r k studies
w i t h f a m i l y responsibilities benefit w o m e n
as w e l l as men, and can lead t o a better
w o r k i n g a t m o s p h e r e for all d e p a r t m e n t
m e m b e r s and s t u d e n t s . The program has
received m a n y more requests for visits
t h a n funding or t i m e a l l o w s . The C S W P
plans t o continue this program, visiting
approximately
three
institutions
per
academic year. Funding w i l l be provided
b o t h by the C S W P and the d e p a r t m e n t
visited.
Women Students in Physics . . . by
Ann McMillan and E. Svensson (continued
from pg. 110)
equality of numbers of w o m e n and men in
the physics profession in Canada.
REFERENCES
1.
Mona Jento: Letter, October, 1 9 8 4 .
2.
" W o m e n in Canada:
A
Statistical
Report". Third Edition, August, 1 9 9 5 ,
ISBN 0 - 6 6 0 - 1 5 5 6 6 - 4 .
3.
Mildred Dresselhaus, Judy Franz and
Bunny Clark: "Improving the Climate for
Women in Physics Departments", The
American Physical Society and the
American
Association
of
Physics
Teachers, 1995.
4.
Roman Czujko: "Realities of the Physics
Job Market"
in Physics
Graduate
Education for Diverse Career Options, ed.
Judy Franz, The American Association of
Physics Teachers and the American
Physical Society, 1 9 9 5 .
TRAVEL G R A N T S F O R W O M E N SPEAKERS
The Travel Grants for W o m e n Speakers
Program is aimed at increasing the visibility
of w o m e n in the field as w e l l as providing
s t u d e n t s , b o t h f e m a l e and male, w i t h
active f e m a l e role models, especially in
those physics d e p a r t m e n t s that do not
have any w o m e n in their f a c u l t y . In the
U . S . A . more t h a n one third of the research
universities have no w o m e n f a c u l t y . APS
reimburses i n s t i t u t i o n s up t o $ 5 0 0 (US) for
the travel expenses of one or t w o w o m e n
speakers.
This program has been v e r y
successful since its establishment and in
1 9 9 3 , the APS Council v o t e d t o increase
its f u n d i n g by one third. All Physics and/or
Science D e p a r t m e n t s in the US are
encouraged t o apply.
Canadian and
M e x i c a n Institutions are eligible also,
provided that one of the invited speakers is
c u r r e n t l y e m p l o y e d by a US Institution.
THE PHYSICS DEPARTMENT SITE VISITS
PROGRAM
The
Physics
Department
Site
Visits
Program is sponsored j o i n t l y by the APS
113
P H Y S I C S I N D I V I D U A L PROFILE - IRINA C O N D R E A
A f t e r I graduated f r o m the U n i v e r s i t y of
(asi in 1 9 8 9 w i t h a degree in p h y s i c s , I
decided t o c o n t i n u e m y studies at the
Bucharest U n i v e r s i t y for a M a s t e r ' s degree
in plasma p h y s i c s . In Romania at that t i m e
there w a s only one M a s t e r ' s degree
program and only 15 w e r e a d m i t t e d each
year. These 15 people w e r e the best
s t u d e n t s f r o m all the Romanian Faculties
of Physics (there w e r e 5 in the c o u n t r y ) .
Since I had a
v,ery
g o o d
a'erage for the
A
.. hole 4 years of
undergraduate
studies, I w a s
accepted
into
the
Master's
program.
The
t i m e period for
taking
the
Master's degree
w a s one y e a r
w h i c h included
3
obligatory
courses during the year, and research w i t h
a thesis at the end. A s I w a s already
interested in a certain subject w h i c h I
presented in m y graduate thesis, I decided
t o c o n t i n u e it. I kept in t o u c h w i t h m y
professor in lasi w h o w a s the head of t h e
plasma physics g r o u p at lasi U n i v e r s i t y ,
but for the m o s t part I had t o deal w i t h m y
p r o b l e m s alone. It w a s a v e r y interesting
experience - I could play w i t h all kinds of
calculations, a s s u m p t i o n s and c o m p a r i s o n s
w i t h other fields of p h y s i c s . Of course, one
year is a v e r y short t i m e for a M a s t e r ' s ,
but in the end I managed t o d e v e l o p an
original v i e w on double layers and on t h e
potential
relaxation instabilities
in a
c o n f i n e d plasma c o l u m n .
I s u c c e s s f u l l y finished m y studies in 1 9 9 0
and, after three m o n t h s , w a s o f f e r e d an 8m o n t h post-graduate f e l l o w s h i p at the
Fusion D e p a r t m e n t of the Energy Research
Centre in Frascati, Italy. M y task w a s to
make s p e c t r o s c o p i c m e a s u r e m e n t s on the
plasma of a m e d i u m - sized t o k a m a k (FTUFrascati T o k a m a k Upgraded). W h e n I
arrived in Italy I had no k n o w l e d g e of the
Italian
language.
Even
though
my
colleagues
spoke
English,
I
soon
u n d e r s t o o d t h a t I needed t o learn t o speak
Italian. A l s o , u p o n m y arrival I had no
k n o w l e d g e about f u s i o n programs. W h i l e I
had learned s o m e t h i n g about the principles
of f u s i o n and t h e use of a t o k a m a k for
nuclear f u s i o n purposes, Romania is t o o
poor
t o be able t o finance s u c h an
i m p o r t a n t p r o g r a m , so f e w there k n o w
a n y t h i n g about it, w i t h the e x c e p t i o n of a
s o m e people at the A t o m i c Institute in
Bucharest w h o collaborate w i t h
other
European Institutions.
This w i l l g i v e y o u an idea of the feeling I
had w h e n I started t o w o r k in the Energy
Research Centre. In Romania I had been
v e r y appreciated for m y w o r k , but here I
f e l t like
a " n o b o d y " . I s t a r t e d t o feel
better after a f e w m o n t h s as m y Italian
i m p r o v e d considerably and I s t a r t e d t o
understand the s y s t e m . C o m i n g f r o m a
place w h e r e y o u d o n ' t
have
many
o p p o r t u n i t i e s t o one w h e r e e v e r y t h i n g is
possible takes a lot of g e t t i n g used t o . I
114
Physics in Canada
M arch/Aprill 9 9 6
w a s certainly
handicapped at
the
beginning by m y origins, by the f a c t that I
w a s Romanian and t h a t I had other w a y s
of looking at things. A d j u s t m e n t depends
on the person also, and I can assure y o u
t h a t f r o m the m o m e n t I understood that
this w a s the case, I made a lot of
progress.
I
was
speaking
Italian
c o m f o r t a b l y after one year ( w i t h o u t taking
any lessons) and I w a s progressing m u c h
more easily in m y field after a f e w m o n t h s .
Because of this, m y director prolonged m y
f e l l o w s h i p for another 8 m o n t h s and also
gave me a lot of responsibilities.
I probably forgot a very i m p o r t a n t aspect
of m y life in those years, m y marriage.
A t that t i m e , m y husband had t o remain in
Romania for bureaucratic reasons. He is
Romanian, too, and y o u m a y not k n o w it,
but in W e s t e r n Europe there are very
s t r o n g l a w s w h i c h impede people f r o m
Eastern Europe f r o m w o r k i n g or staying for
extended periods in other c o u n t r i e s . I could
say plenty about the reasons for those
l a w s , but I d o n ' t think it w o u l d resolve
a n y t h i n g . The point is that nobody f r o m
the Italian authorities w a n t e d t o k n o w
about the presence of m y husband in m y
life. S o m e t i m e s I even got the suggestion
t o " f i n d yourself an Italian and marry him
and y o u r problems w i l l be r e s o l v e d " . No
c o m m e n t . A f t e r almost 1 0 m o n t h s , I
managed to get a w o r k permit and a j o b
for m y husband. He is a metallurgical
engineer w i t h excellent skills so it w a s n ' t
really very d i f f i c u l t t o find an appropriate
j o b for him even if he had t o t o t a l l y change
fields (to m i c r o - m e c h a n i c s ) . W e started t o
have a happy life, w e w e r e 9 0 % adjusted
t o Italian society and w e had a f e w very
g o o d friends. The problems appeared w h e n
the 8 m o n t h f e l l o w s h i p w a s c o m i n g to an
end and I had no place t o go. A c c o r d i n g t o
their l a w s I had t o leave Italy. M y director
proposed a 2-year long research c o n t r a c t ,
very well
paid and including
some
expenses for conferences, w o r k visits etc.
There w a s a lot of w o r k but I accepted
i m m e d i a t e l y because I loved m y w o r k and
I loved Italy.
The years in Italy w e r e very happy for me
and m y husband. There w e r e still some
clouds in our s k y and once again it w a s
our w o r s t enemy- the authorities. M y
husband because of his w o r k permit could
s t a y in Italy as long as he w o r k e d but I had
entered Italy w i t h a student visa and even
t h o u g h I w a s w o r k i n g , I c o u l d n ' t get a
w o r k visa. So, after the 2 year c o n t r a c t I
w a s supposed t o leave Italy. This s i t u a t i o n
caused us a lot of despair. Only someone
w h o has lived w i t h this s i t u a t i o n can k n o w
w h a t I mean.
Fortunately, w e are positive thinkers and
so, 6 m o n t h s before the end of m y
c o n t r a c t w e discussed our f u t u r e plans
v e r y seriously. Should I remain in physics?
It seemed very d i f f i c u l t for 2 reasons apart
f r o m m y visa: first- only an Italian citizen
can be hired in a research Institute because
it is state-run; second - industry is not v e r y
interested in hiring physicists and if they
do it is for s o f t w a r e d e v e l o p m e n t . Should
w e stay in Italy? W h e r e w o u l d w e go?
There w a s no w a y that w e could go back
t o Romania. A f t e r serious t h i n k i n g , I
decided that I'd like t o continue m y studies
t o a PhD degree and m y husband agreed.
Tired of the problems w e had because of
our citizenship, w e decided t o emigrate t o
Canada.
Here w e are n o w , in M o n t r e a l , Canada. I
am doing m y PhD studies in fusion at the
Centre Canadien de Fusion M a g n é t i q u e ,
Varennes. I intend t o measure the ion
t e m p e r a t u r e and the i m p u r i t y d e n s i t y in the
central plasma of T o k a m a k de Varennes by
injecting a neutral beam in the plasma. I t ' s
an interesting and c o m p l e x subject. I have
already finished all the courses and I have
started to w o r k on m y research s u b j e c t .
M y husband f o u n d a j o b in a metallurgical
c o m p a n y , w h e r e he is p r o d u c t i o n manager.
W h e n w e arrived here, w e again felt like
w e w e r e " n o b o d i e s " because w e d i d n ' t
speak French (even t h o u g h w e had studied
it in school) and also because this s o c i e t y
is d i f f e r e n t f r o m the European one. I think
that I can say at this point that w e have
once again managed to adjust t o this
s o c i e t y . W e n o w b o t h speak English and
French and w e feel w e l l integrated in our
w o r k groups. W e have Romanian and
Canadian friends and w e love all the
occasions in w h i c h w e can make n e w
c o n t a c t s w i t h people f r o m all around the
world.
M a y b e y o u ' l l say that I w r o t e t o o m u c h
about our problems w i t h visas instead of
speaking about physics. W e l l , in m y life,
both things w e r e correlated. It is sad t o
see h o w m a n y i m p e d i m e n t s a Romanian
scientist has t o face if she/he w a n t s t o
continue their c h o s e n career.
Still, I d o n ' t regret being a w o m a n in
physics. M y male colleagues continue t o
tell me that w e , the w o m e n , have a lot of
advantages in our w o r k field. I d o n ' t think
so. Even if there are l a w s w h i c h are
supposed t o help w o m e n , I find it v e r y
d i f f i c u l t t o o b t a i n a position.
Males
continue t o say that t h e y w a n t t o have
w o m e n in their labs but w h e n they have t o
sign for a position t h e y prefer a man.
There are special cases
such as
my
director in Frascati, Dr. R. Bartiromo, w h o
never made me feel like I w a s a w o m a n ;
he considered me first and f o r e m o s t as a
physicist. I am v e r y grateful t o him
because he never abused his p o w e r and he
o f f e r e d me the o p p o r t u n i t y t o change m y
career and m y life. Our male colleagues are
not used t o having w o m e n in their labs and
I think t h a t is up t o us, the w o m e n , t o
s h o w t h e m that w e can speak about
physics w i t h t h e m and that w e are capable
of doing g o o d research. W e have t o
cooperate, t o give the best of ourselves
and also t o accept differences in each
other.
I d o n ' t k n o w if the fact t h a t I ' m a married
w o m a n changes a n y t h i n g in m y career.
Certainly it w a s not easy for b o t h of us t o
change countries and jobs, but w i t h a bit
of reciprocal understanding w e
have
managed t o have a happy life. Even n o w
that I k n o w h o w d i f f i c u l t it is t o get a job
in physics I w o u l d still choose t o do this.
I ' m sure that all the w o m e n p h y s i c i s t s can
make important c o n t r i b u t i o n s t o p h y s i c s .
PHYSICS INDIVIDUAL PROFILE - NANCY REMAGE EVANS
Where did I start? I went to university with
an interest in science but not an exclusive
interest. It wasn't until s e c o n d year that
almost by accident I selected a course in
astronomy, a n d after that I was hooked. I
have thought about whether the fact that I
was at a w o m e n ' s college (Wellesley) had
an effect. As with many areas, there are
probably pros a n d cons.
Certainly the
a t m o s p h e r e in the 1960's (graduated 1966)
which e m p h a s i z e d serious career choices
for w o m e n and classes where there was no
pretending they were really a i m e d at
s o m e o n e else were highly beneficial.
A m o n g things that particularly excited m e as
an undergraduate were the way in which
clusters of stars provided information about
the physics of the ev<?lution of stars
fundamental data such as the m a s s e s of
stars. Altough I would not have g u e s s e d it at
the time, I have continued to work in s o m e of
the s a m e areas, largely because of the
exciting new observations which have
b e c o m e possible both because of technical
a d v a n c e s in g r o u n d - b a s e d observations and
a l s o n e w w a v e l e n g t h regions m a d e a v a i l a b l e
throughofsatelliteobservations. E n c o u r a g e d
by graduation with honours a n d m e m b e r s h i p
in Sigma Xi, I continued to graduate school,
supported by a variety of fellowships.
For graduate school, I c a m e to the
Astronomy Department at the University of
Toronto,
where
I did a
thesis
on
observations of variable stars, supervised by
Dr. J.D. Fernie. It is possible to determine
the radii of pulsating stars by c o m b i n i n g
m e a s u r e m e n t s their light, color, a n d velocity
variations.
This was m y first work on
Cepheid variable stars, which are particularly
important in the determination of distances
to galaxies b e y o n d our o w n Milky W a y
galaxy. (As a Hubble Space Telescope key
project, C e p h e i d s were featured in a TIME
magazine cover story last year).
This period was the beginning of the juggling of
career demands with family
demands,
culminating with the arrival of a second child
and a thesis at nearly the same time. This
combined with a husband with tenure (Marting
G. Evans, Professorof Organization Behavior
in the Faculty of Management Studies at the
University of Toronto) limited possibilities to
travel for a
post-doc.
It
was
quite
fortunate that Dr. J.R. Percy offered me a parttime post-doctoral fellowship at the University of
Toronto. Though I continued to observe at
David Dunlap Observatory (DDO) in Richmond
Hill, Ontario, I concentrated on different aspects
of spectroscopy than before.
In this case, the masses of Cepheids were
badly needed to confirm our understanding
of the physics of the history of the stars,
particularly since they are so important in
extragalactic distances.
In order to
determine masses, pairs of stars in binary
systems are needed.
Although it was
thought at the time that no suitable Cepheid
binaries existed, velocity observations at
D D O (and elsewhere) began to turn up
candidates for orbit determinations.
This
s a m e approach also led to information about
h o w frequently binary systems occur. This
is important information about star formation
(are stars likely to form single or in pairs or
groups?) which is a very active research
area currently. Ultimately it has bearing on
h o w frequently conditions n e e d e d to form
planetary systems exist.
In the family/career area during this period
as I began to search for a permanent job, I
sometimes w o n d e r e d whether cover letter
statements that the work had been done
part-time w e r e really taken into consideration
w h e n evaluating productivity. Likewise, one
can only hope that cover letter statements
about a variety of experience are considered
as strong a proof of broad experience as
physical mobility.
There is a lively debate at the m o m e n t in the
weekly email newsletter on w o m e n ' s issues
from the A m e r i c a n Astronomical Society
about the best age is to have children during
a scientific career.
Perhaps the most
healthy aspect of the discussion of a
complex problem is the diversity of opinions
ranging from early (the energy factor is
important)
to
waiting
until
you
are
established. I can certainly attest that while
it was not easy to do both graduate work
and post-doctoral work on a part time basis,
that is option which I found to be workable
as well as very rewarding.
After a year of teaching at Erindale College
at the University of Toronto, I took a position
as Resident Astronomer at the International
Ultraviolet Explorer satellite (IUE) run from
NASA's Goddard S p a c e Flight Center just
outside of Washington, D C., USA. This is
a small astronomical statellite for which half
a d o z e n astronomers supervised all aspects
of the project: taking the data, data
processing, and assisting with the scientific
analysis with visiting astronomers. Working
with a small team on such a breadth of
projects was an exciting and d e m a n d i n g
experience, a n d left m e at times busier than
I have ever been.
In my own research, adding the ultraviolet
observations to the long-term velocity
observations I had been making in Ontario
provided the ability to attack many scientific
questions. A mass determination of the
Cepheid SU Cyg b e c a m e possible by
measuring the velocity of its hot c o m p a n i o n
using the IUE satellite (with Dr. C.T. Bolton,
University of Toronto). This has lead directly
into a more extended program of additional
stars (Bohm-Vitense, Evans, Carpenter, a n d
Robinson) using the more powerful Hubble
S p a c e Telescope. In addition, further work
on Cepheid c o m p a n i o n s using both the IUE
and Voyager satellites has given m u c h
clearer information about binary frequency
a n d about the importance of rotation of
mixing in stellar evolution. So far the 39
successful
statellite
proposals
have
contributed to 45 refereed publications (and
n u m e r o u s conference proceedings).
The family situation was more complicated.
After 3 years of looking (involving a combination
of commuting and sabbatical leave), my
husband was not able to find a position in the
area. We moved back to Toronto, where I
continued research on soft money. When the
Institute for Space and Terrestrial Science
(ISTS) was set up as one of the Ontario
Centres of Excellence, I took a scientific position
in the Space Astrophysics Laboratory (SAL,
1988) and eventually became Associate
Director of the Laboratory.
In addition to research, we worked on a
n u m b e r of astronomical statellite projects
sponsored by the Canadian Space Agency.
The scientific background in S A L allowed us
to have interaction with small Ontario high
tech c o m p a n i e s with interests in space
related technology. During this period, I also
b e c a m e and Adjunct Profesor at York
University, a n d was pleased to find that my
applications for operating grants to the
Natural Science and Engineering Council,
C a n a d a (NSERC) were well received a n d
my grants continued to increase.
This
meant that I was able to support several
graduate students, as well as undergraduate
s u m m e r a n d work study students.
They
worked mainly on projects usually using
satellite data, though this was often
c o m b i n e d with data obtained at DDO.
Unfortunately in 1994 a decision was taken
at the Institute to reduce science and
concentrate only on industrial work and the
laboratory was closed. I looked for work
extensively in C a n a d a for a year.
In 1995, I was offered a position at the
Harvard Smithsonian Center for Astrophysics
to
work
on
the
Advanced X-Ray
Astrophysics Facility (AXAF) a n d I relocated
to Boston. The work on this project which is
NASA's next major satellite project is very
exciting, as is readjusting my research to
another wavelength region. High energy
studies with this satellite are promising ways
to provide a better understanding
of
magnetic
activity
in
stars
(including
Cepheids). Such activity (the sunspot cycle)
has important effects on many p h e n o m o n a
on earth, such as communications a n d
growth cycles. I also hope s o m e work on
star
clusters
will
lead
to a
better
understanding of processes producing Xrays in hot stars.
C o m m u t i n g between Boston a n d Toronton
(where my husband is) is also requiring some
readjustment, although it is possible now that
the children are in university and graduate
school. I can only thank my husband for his
support in this crazy existence!
Can I predict what is next? I wouldn't dare either in science or in job title.
115
P H Y S I C S I N D I V I D U A L PROFILE - D I A N E P I N S O N N E A U L T
A 31 ans, physicienne, je travaille depuis 4
ans pour l ' I n s t i t u t National de la Recherche
matière sont peu familiers sur terre mais
réaliser des appareils pour mesurer
très répandus dans l ' u n i v e r s . Une matière
paramètres du plasma eit de les
des
rendre
m y s t é r i e u s e pour laquelle j ' a i développée
disponibles. Dans le but de favoriser les
un grand intérêt.
collaborations internationales et l'échange
v i n g t a i n e a f f e c t é s au laboratoire du Centre
Partagée entre le désir d ' ê t r e c o n f r o n t é e à
des articles scientifiques et assister à des
Canadien de
Fusion
pour
la f u s i o n dans
Scientifique
INRS-Énergie,
un centre de
recherche universitaire dans le groupe de
de connaissances, on est appelé à rédiger
physique des plasmas. Nous s o m m e s une
étudier
transformer
la
un milieu industriel et celui d ' a c q u é r i r une
congrès,
de
bonne connaissance théorique des plasmas
s o u v e n t . Ceci me permet de diversifier
énergie.
ainsi que de découvrir leurs applications, je
m o n expérience et d ' é t e n d r e
mes connaissances.
Magnétique
matière
CCFM
le but
en
Pourtant, bien que c o m m e pour la plupart
me t r o u v a i s très heureuse quand j ' a i eu
de mes collègues, la carrière dans laquelle
l'occasion
je me t r o u v e
recherches au C C F M .
n'était
pas m o n
premier
maîtrise
choix.
de
en
combiner
études
des
qui
m'amène
à
voyager
davantage
et
J ' a i entrepris une
physique
ce
plasmas
à
Une carrière en science est exigeante, je
suis souvent amenée à faire un choix entre
l ' U n i v e r s i t é de M o n t r é a l sous la d i r e c t i o n
ma carrière et ma vie personnelle.
Du plus loin de
d'un
début,
mes souvenirs,
C C F M . Ce centre participe à un p r o g r a m m e
d'acquérir
je m'émerveillais
mondial
d'une
faire mes preuves. Il faut s'intégrer à son
devant
source d'énergie viable à long t e r m e à
milieu de travail. A u C C F M , le milieu est
ressources de la
partir
moins
nature
et
intéressant qui me plaisait. À Varennes,
comment
elles
près de M o n t r é a l , le centre exploite une
sont majoritaires, j ' é t a i s intimidée par la
pouvaient
être
machine de t y p e t o k a m a k , T d e V ( T o k a m a k
c o m p l i c i t é dont ils f o n t preuve entre eux.
de
Cependant, j ' a i su développer des a f f i n i t é s
les
transformées en
professeur
pour
de
qui
le
la
était
développement
fusion,
Varennes),
membre
qui
un
du
aspect
permet
de
fort
confiner
j'ai
du
m'engager
à
les c o m p é t e n c e s
compétitif
institutions.
que
Dès le
fond
afin
requises
dans
et
d'autre
En sciences, où les h o m m e s
nouvelles
e f f i c a c e m e n t le plasma afin d ' é t u d i e r la
avec
applications. Je
f u s i o n . La c o m p l e x i t é d ' u n projet de cet
atmosphère de travail agréable.
m'interessais à
ampleur
d'équipe
que j ' a i toujours soigné mes relations. Bien
la mécanique et
c o m p o s é e de chercheurs, d ' i n g é n i e u r s , de
encadré, je suis encouragée et souvent
à l'outillage de
techniciens et d ' i n f o r m a t i c i e n s . Ce milieu
épaulée par mes camarades de travail.
^^^^^^^^^^^^^^^
I
exige
l'atelier de m o n père. Le s o u t i e n de ma
multidisciplinaire
famille a joué un rôle d é t e r m i n a n t
un
qui
travail
fait
appel
à
certains
confrères
créant
une
J'avoue
la
technologie de pointe et à l'expertise des
A u C C F M , c ' e s t l'état qui s u b v e n t i o n n e la
ont
entreprises
industrielles
de
recherche à long t e r m e . C o m p t e tenu du
suscité chez moi le désir d ' i n d é p e n d a n c e et
développer
des
une
c o n t e x t e é c o n o m i q u e actuel, l'avenir du
de réussite.
expérience en recherche scientifique. J ' a i
centre est incertain et les perspectives de
dû
carrière en physique sont peu nombreuses.
mon
cheminement.
'était
Mes
Pour ma mère,
prioritaire.
dans
parents
l'éducation
Fascinée
par
la
acquérir
la
m'a
permis
connaissances
formation
et
voulue
pour
t r a n s f o r m a t i o n de la matière et curieuse de
travailler au sein de c e t t e équipe dont la
D'après une c o n v e n t i o n , une carrière de
nature, le génie c h i m i q u e répondait à mes
qualité des t r a v a u x est reconnue. Ce fut
scientifique requiert un d i p l ô m e PH.D et de
les
une expérience parfois d i f f i c i l e mais qui
plus en plus un
sciences se sont imposées d'elles m ê m e .
s ' e s t révélée très enrichissante. C o m m e de
mener
J e n'ai d o n c pas hésité à m ' e n g a g e r dans
f a i t , avant la f i n de ma maîtrise, le CCFM
contre, je ne regrette pas m o n c h o i x . A v e c
une
m'a
q u ' u n d i p l ô m e de maîtrise, je suis
aspirations.
A u m o m e n t du c h o i x ,
carrière
en
sciences
appliquées.
proposé
un
poste,
alors
que
les
leurs
post d o c t o r a t
propres
afin
expériences.
de
Par
très
Cependant, durant mes études au cégep,
emplois en science se faisaient rares. M o n
heureuse d ' a v o i r un emploi qui me permet
u n excellent professeur de physique, un
c h e m i n e m e n t académique a pris f i n et je
de faire de la recherche et de me m e t t r e en
bon vulgarisateur
me suis jointe à l'équipe du centre.
Ma
valeur. Pour le m o m e n t , mes récompenses
c a p t i v e r et susciter m o n intérêt pour la
m o t i v a t i o n à devenir professionnelle m ' a
résident plus dans la s a t i s f a c t i o n du travail
physique.
permis de rédiger m o n m é m o i r e de maîtrise
bien fait que dans le salaire ou la stabilité
t o u t en o c c u p a n t un poste de chercheur.
d'emploi.
lors, c ' é t a i t décidé, j'allais poursuivre des
Je suis très satisfaite de m o n emploi qui
Jusqu'ici,
études en physique. A p r è s l ' o b t e n t i o n de
est
qu'exigeant.
remplie, je vois évoluer mes intérêts et
multiplier mes a c t i v i t é s qui s ' é t e n d e n t de la
Il
scientifique
m'a
fait
a su
découvrir
me
la
s a t i s f a c t i o n de c o m p r e n d r e le f o n d des
choses et le défi que ça représente. Dès
mon
diplôme
Montréal,
j'ai
B.Sc.
de
décidé
supérieurs.
représentent
116
le
avec
une carrière aussi
bien
de
Responsable d ' u n projet d ' é q u i p e , je dois
continuer
ma
entre autre, gérer un budget, faire des
musique
études
la
discipline, l'organisation et la persévérance
qui
p r o g r a m m a t i o n , m e t t r e en application mes
me p e r m e t t e n t de concilier ma carrière et
la
connaissances acquises pour concevoir et
mes multiples intérêts.
Les
quatrième
Physics in Canada
enrichissant
l'Université
de
f o r m a t i o n en physique des plasmas aux
études
aussi
plasmas
état
de
M arch/Aprill 9 9 6
scientifiques,
faire
de
à la
plongée
sous-marine.
La
P H Y S I C S I N D I V I D U A L PROFILE - D E B O R A H POIRIER
I have loved science since I w a s a little
girl, d r a w i n g m o u l d spores in grade t w o
and
sitting
on
the
balcony
in
a
t h u n d e r s t o r m w i t h m y father t o w a t c h the
lightning.
Neither of m y parents is a
scientist, but b o t h have a l w a y s s h o w n a
great deal of respect for the sciences and
b o t h gave me a s t r o n g sense t h a t it w a s a
v e r y honourable career t o pursue. In high
school, I t o o k extra p h y s i c s and biology
classes and decided t h a t I w a n t e d t o
become a d o c t o r , since I e x p e c t e d that it
involved diagnosing and puzzle-solving. I
began CEGEP in a health sciences p r o g r a m
w h i c h included m a n d a t o r y humanities and
literature c o u r s e s , w h i c h I v i e w e d as a
dilution of m y studies. H o w e v e r , m y m i n d
q u i c k l y changed on that point - w i t h i n one
semester I had changed into a social
sciences p r o g r a m and declared c o n f i d e n t l y
t o m y s h o c k e d m o t h e r t h a t I w o u l d NEVER
t a k e calculus again.
^•ffljj^^
^ H r ^ ^ ^ k
^ H ^ ^
J^fc
• '
|
'
During m y t w o years
in CEGEP I b e c a m e
involved
in
the
school
newspaper,
The
Champlain
Bugle, w o r k i n g as
c o p y editor and later
as
news
editor.
W h e n one of m y
stories w a s picked
up by the Canadian
U n i v e r s i t y Press I
seriouslyentertained
the
idea
of
b e c o m i n g
a
journalist, and even
w o r k e d a f e w evenings at the McGill Daily.
I began dating the e n t e r t a i n m e n t s editor, a
y o u n g blues m u s i c i a n , w h o i n t r o d u c e d me
t o jazz. (That w a s 1 4 years ago.
Now
HE's a d o c t o r and w e ' r e still t o g e t h e r . . . ) I
took courses in Middle East politics,
philosophy, and T V p r o d u c t i o n , and made
friends w h o spent their a f t e r n o o n s painting
and sculpting. But s l o w l y I began to long
once again for the s t r u c t u r e and discipline
of science, and added a b i o l o g y class as an
elective. I decided t h e n and there that I
w a s far more c o m f o r t a b l e and happy w h e n
t h i n k i n g about science, and began applying
t o u n i v e r s i t y science p r o g r a m s . I suppose
w e d o n ' t ever really k n o w w h a t ' s g o o d for
us, but in r e t r o s p e c t , I a m g r a t e f u l that I
had the o p p o r t u n i t y for m y brief f o r a y into
the arts, w h i c h opened before me a w h o l e
new world.
^b
I t h e n had t o pick a major t o w r i t e on m y
application
forms.
I can credit
(or
blame) M r Fahmi, m y high school physics
t e a c h e r , for m a k i n g m y decision for me,
a l t h o u g h he probably d o e s n ' t k n o w it. He
w a s the t y p e of teacher w h o s e e n t h u s i a s m
for understanding physical s y s t e m s w a s
infectious.
He turned exploring physics
into an e x c i t i n g journey w i t h lots of handson laboratory
work
and
problemsolving. M r . Fahmi only gave oral e x a m s ,
because he w a s m o s t interested in seeing
us think a problem t h r o u g h , rather t h a n
m e m o r i z e a proof and d u t i f u l l y scribble it
down.
I have since read t h a t some girls learn
science
better
when
it
is
taught
i n t e r a c t i v e l y and t h e y are g i v e n solid,
hands-on e x a m p l e s of t h e c o n c e p t s that
t h e y ' r e t r y i n g t o grasp.
That certainly
holds for me, so it w a s a natural choice for
me t o t u r n t o e x p e r i m e n t a l physics as an
undergraduate at Concordia U n i v e r s i t y . Up
until m y arrival there, it h a d n ' t really
o c c u r r e d t o me t h a t physics w a s an
unusual choice for a girl. M y f a m i l y had
a l w a y s s u p p o r t e d m y scientific leanings,
taking me t o the library e v e r y w e e k e n d
w h e n I w a s a girl, and telling me that
absolutely a n y t h i n g w a s possible. Being
the only child of a father w h o w a s (and is)
a born tinkerer ended up being excellent
preparation for e x p e r i m e n t a l w o r k .
We
w o u l d build things t o g e t h e r and f r e q u e n t l y
go t o t h e lumber yard or the h a r d w a r e
store for provisions. I e x p e c t t h a t had I
had a brother these " u n f e m i n i n e " pursuits
m a y have fallen t o him, but I guess I just
got l u c k y l By the t i m e I m o v e d into m y
first a p a r t m e n t , I could tune a car, and
change m y brakes.
Despite m y M r . f i x - i t upbringing, I still had
the feeling t h a t m e n just magically k n e w
about all things mechanical, and cars in
particular.
That n o t i o n w a s
finally
dispelled one day w h e n I w a s w o r k i n g on
m y car in m y parents' d r i v e w a y . I had
m o v e d out a year earlier, but still returned
t o the house t o do car m a i n t e n a n c e in case
I should get myself into a j a m . M y father
came out t o look at w h a t I w a s doing and
after a w h i l e I realized that I k n e w more
a b o u t m y old car than he did,
mainly
because I had spent so m a n y hours
banging a w a y at it w i t h the shop manual in
m y hand.
I learned that he d i d n ' t
necessarily k n o w every detail about f i x i n g
cars, but he had the c o n f i d e n c e t o tackle
any problem that c a m e up. I did m y next
big car j o b in m y o w n d r i v e w a y .
M y graduating class at Concordia had all of
six s t u d e n t s , w i t h t w o w o m e n .
The
previous year had one, so I a l w a y s had
w o m e n in m y s t u d y g r o u p s , and t o g e t h e r
w e w e r e v e r y i n v o l v e d in the society of
p h y s i c s s t u d e n t s . W e also all w o r k e d as
lab d e m o n s t r a t o r s and course markers.
One single w o m a n did h o w e v e r lament
t h a t her c h o s e n field w a s hardly an
aphrodisiac t o suitors.
W e f o u n d that
most y o u n g men's reactions to our being
in physics fell into t w o categories:
the
" Y o u m u s t be s m a r t " ,
and the "Hah! I
failed that in high s c h o o l " .
M y single
friend w a s v e r y pleased w h e n one f e l l o w
said, " O h , e = m c 2 ! " . I think that w e all
felt c o m f o r t a b l e and a c c e p t e d in the
d e p a r t m e n t and d i d n ' t necessarily feel an
imbalance. The only problem t h a t came up
w a s a v i s i t i n g lecturer s h o w i n g slides of
s c a n t i l y clad w o m e n during the course of
a serious talk.
From Concordia I w e n t on t o INRS-Energie,
a graduate a r m of Université du Q u é b e c , t o
do a M a s t e r ' s degree in plasma p h y s i c s . I
carried out m y e x p e r i m e n t a l w o r k on
T o k a m a k de Varennes, C a n a d a ' s largest
f u s i o n f a c i l i t y . I a m n o w nearing the end of
m y d o c t o r a t e , and actually have the
pleasure of sharing a lab setup w i t h
another w o m a n .
W h a t happens after I
finish is a n y o n e ' s guess!
At an A m e r i c a n Physical S o c i e t y m e e t i n g
of the Division of Plasma Physics a f e w
years ago, I a t t e n d e d a w i n e and cheese
for w o m e n in p h y s i c s , along w i t h the 2 0 or
so other w o m e n delegates (and at least as
m a n y hungry men). Until t h e n I d o n ' t think
I ever really felt the impact of the lack of
w o m e n in physics. It w a s a real pleasure
t o meet these w o m e n , especially the more
established p h y s i c i s t s , as until then I had
yet t o meet a senior e x p e r i m e n t a l i s t w h o
w a s a w o m a n . One even c a m e along w i t h
her physicist husband and their baby.
Since t h e n I have c o m e t o the s t r o n g belief
that role models are essential for y o u n g
w o m e n considering science as a career. It
helps e n o r m o u s l y t o see s o m e o n e like y o u
s u c c e s s f u l l y doing the thing for w h i c h y o u
are training. G y m n a s t s and divers have t o
visualize d i f f i c u l t m o v e s before t h e y can be
a t t e m p t e d . Perhaps the same is true for
y o u n g w o m e n in p h y s i c s .
It w a s after t h a t APS m e e t i n g t h a t I
met A n n M c M i l l a n and Eric Svenssen, t w o
tireless m e m b e r s of the C o m m i t t e e t o
Encourage W o m e n in Physics of the CAP.
W e and several others have w o r k e d
t o g e t h e r over the past several years t o
c o n s t r u c t i v e l y change the face of p h y s i c s ,
and this special issue on w o m e n is just one
of the w a y s . W e hope y o u like it.
117
P H Y S I C S I N D I V I D U A L PROFILES - R E N A I S S A N C E W O M E N
It has long been a m y s t e r y t o sociologists
and e d u c a t o r s w h y more w o m e n t e n d t o
s t u d y the liberal arts t h a n the m a t h e m a t i c a l
sciences. This could be caused by m a n y
reasons, including t h e influence of society
or biological d i f f e r e n c e s bet w e e n the sexes.
M y purpose here is not t o e x a m i n e these
reasons, but rather, t o present the s t o r y of
four y o u n g Canadian w o m e n w h o are
presently finishing their f i f t h and final years
at M c M a s t e r U n i v e r s i t y having c o m p l e t e d
the requirements for b o t h honoursPhysics
and
Arts
degrees.
During
their
undergraduate
education
they
have
explored b o t h sides of c a m p u s and have
f o u n d t h a t p e r s p e c t i v e s f r o m the arts and
sciences are o f t e n c o m p l e m e n t a r y .
Michelle Hilts
Michelle Hilts w a s born and raised in Deep
River, O n t a r i o , but jokes t h a t her parents
are the o n l y t w o non-physicists in t o w n .
Her father teaches physical e d u c a t i o n and
history and her m o t h e r art and english at
the local high school. W i t h an arts and
science b a c k g r o u n d , M i c h e l l e had a l w a y s
planned t o s t u d y b o t h areas at u n i v e r s i t y .
She w a s enticed into Physics in first year
w h e n her professor urged her to apply for
the Targeted NSERC S u m m e r A w a r d .
A f t e r t w o years of intense Physics training,
Michelle longed for s o m e v a r i e t y in her
studies. She decided t o include a f e w more
A n t h r o p o l o g y courses in her program and
w a s later surprised t o learn t h a t t h e t w o
fields w e r e c o n n e c t e d . Last s u m m e r
Michelle had the o p p o r t u n i t y t o use Physics
w i t h A r c h a e o l o g y in a s u m m e r NSERC
a w a r d held at S i m o n Fraser U n i v e r s i t y . She
w o r k e d w i t h Dr. Erie Nelson
using
M a g n e t o m e t e r y t o search for buried earth
ovens.
Michelle believes that Physics has helped
her studies in A n t h r o p o l o g y by g i v i n g her
the
ability
to
approach
problems
analytically. She finds that she has profited
f r o m a s t u d y of A n t h r o p o l g y by becoming
a more c o m p l e t e person and by gaining a
greater
understanding
of
humanity.
Michelle is planning t o explore
the
c o n n e c t i o n s b e t w e e n t h e t w o fields in
more d e p t h d u r i n g graduate studies in the
application of Physics t o A r c h a e o l o g y .
118
Physics in Canada
M arch/Aprill 9 9 6
Catherine Lucas
A s long as she can r e m e m b e r , Catherine
Lucas has a l w a y s been interested in
science. She enjoys the theoretical aspect
of Physics and, like Michelle, w h a t started
as an elective blossomed into a major
interest. Catherine w a s interested in a
w i d e v a r i e t y of areas and w a n t e d t o
c u l t i v a t e n e w ideas and develop necessary
skills. Catherine is f i r m l y opposed t o the
segregation of the arts and sciences, and
is encouraged by the recent trend in
universities t o p r o m o t e interdisciplinary
fields.
Catherine f o u n d t h a t Physics enabled her
t o bring a logical and s y s t e m a t i c v i e w p o i n t
t o C o m p a r a t i v e Literature. A p a r t f r o m the
obvious enhnacement of w r i t i n g skills, she
believes t h a t C o m p a r a t i v e Literature has
other c o n t r i b u t i o n s t o make t o Physics.
She says: " C o m p a r a t i v e Literature is the
s t u d y of literature in d i f f e r e n t languages.
The central problem of
Comparative
Literature is: h o w m u c h of the meaning is
lost in translation? A n interesting problem
for the physicist t o think about is, w i t h
Mathematics
being the
language
of
Physics, do w e lose meaning in the
t r a n s l a t i o n t o verbal language?" Since it is
with
language
that
we
teach
and
c o m m u n i c a t e physics t o other people, h o w
can w e be sure that the presented picture
is complete?
Soumi Ghosh
Soumi Ghosh is the kind of student w h o
just w a n t s t o k n o w e v e r y t h i n g . She
t h o u g h t Physics w o u l d be a good place t o
s t a r t . Her interest in Psychology began her
s e c o n d year of university and she has
sampled a variety of courses covering
e v e r y t h i n g f r o m abnormal Psychology t o
Neuroscience. She v i e w s the psyche as a
'black b o x ' and n o w seeks t o k n o w w h a t
it is t h a t makes us t h i n k and act in t h e
w a y that w e do. For Soumi, it is t h r o u g h
Physics that one tries to find t r u t h in the
universe and it is t h r o u g h Psychology that
one tries t o find t r u t h in h u m a n s .
She
plans t o bring these ideas together t h r o u g h
graduate studies in the Philosophy of
Science.
Soumi c o n t e n d s that s t u d y i n g Physics has
helped her appreciate the material side of
h u m a n behaviour. A n d h o w does she see
Psychology influencing Physics? "Theories
in Physics are v e r y m u c h m o t i v a t e d by the
personality t y p e of the kind of person that
studies Physics. Think of h o w Mozart or
M o n e t or even Karl Marx w o u l d have
described Physics and h o w their theories
might have g i v e n Physics n e w i n s i g h t s . "
Soumi
believes
that
by
studying
Psychology w e can eliminate the h u m a n
bias
in
science
and
come
to
an
understanding of the f u n d a m e n t a l s of the
universe.
Carrie Klatt
A s for me, I am finishing o f f
my
undergraduate
studies
in
theoretical
Physics and Philosophy.
A f t e r m y first
f e w years of Physics I w a s disillusioned by
the fact that I could n o w solve m a n y
mathematical
and
artificial
Physics
problems but, I had not y e t had an
o p p o r t u n i t y t o q u e s t i o n the f o u n d a t i o n s of
w h a t I w a s being t a u g h t . I have f o u n d
that the t w o subject areas have a great
deal t o o f f e r one another. Physics o f f e r s
Philosophy more problems t o w o r k on and
provides an alternative understanding of
the universe. For me, it w a s Philosophy
t h a t gave Physics back its beauty.
Its
critical style opened n e w arenas t o
consider and various interpretations t o t r y .
I f o u n d t h a t it w a s only t h r o u g h a
c o m b i n a t i o n of the t w o that I w a s able t o
make sense of either.
A f t e r asking m y three classmates about
their interests and opinions, t w o points
became o v e r w h e l m i n g l y obvious. First, w e
all agreed t h a t t o d a y , especially
in
academia, w e are c o n f r o n t e d w i t h the
problem
of
specialization.
To
know
s o m e t h i n g so deeply at the expense of
h o w it relates t o other areas is t o not
k n o w it c o m p l e t e l y .
A s a result,
specialization, especially at an early point
in o n e ' s education, proves limiting.
As
students and scientists it is important to
appreciate the position of others and h o w
their interests relate t o our o w n .
Second, as expressed m o s t clearly by
Michelle, " w o m e n aren't m e n and the
shouldn't t r y t o b e " . Even t h o u g h w o m e n
have the same potential and interest in
Physics as do men, t h e y o f t e n bring a
d i f f e r e n t v i e w p o i n t t o the s t u d y .
Soumi
c o m m e n t e d that I could have done this
article on m e n and w o m e n w h o are
s t u d y i n g A r t s and Physics but m o s t of m y
examples w o u l d still have been w o m e n . It
w o u l d seem, at least for this g r o u p of
students, that there is s o m e t h i n g in the
liberal A r t s that is not in Physics t h a t w e
just c a n n o t , and perhaps, should not, do
w i t h o u t . If w o m e n have a natural interest
in more A r t s y endeavours then this w i l l
add t o the diversity in Physics. W o m e n
also develop d i f f e r e n t approaches t o
problems and introduce a w a r m e r and
more cooperative e n v i r o n m e n t . Basically,
w e bring those things t o the Physics
c o m m u n i t y that are part of w o m e n and not
of men.
The moral of the s t o r y is that as w o m e n in
physics, w e do not need t o enter the
profession as sheep in w o l v e s ' c l o t h i n g in
order t o be successful and p r o d u c t i v e .
There are special a t t r i b u t e s that a f e m a l e
presence brings t o the c o n t e m p l a t i o n of
the universe. Their specific interests can
only add a n e w d i m e n s i o n t o the s t u d y of
Physics.
P H Y S I C S I N D I V I D U A L PROFILE - M A R Y A N N E W H I T E
Dr. M a r y A n n e W h i t e has been a m e m b e r
of the C A P since shortly after receiving her
PhD, although all her degrees are in
c h e m i s t r y . H o w e v e r , she has long been of
the opinion that physics and c h e m i s t r y are
v e r y , closely related subjects.
Indeed,
some of the m o s t interesting science
occurs at the interface b e t w e e n physics
and c h e m i s t r y .
A native of London, Ontario, M a r y A n n e
graduated f r o m the U n i v e r s i t y of W e s t e r n
Ontario in 1 9 7 5 w i t h the A l u m n i Gold
M e d a l in C h e m i s t r y . Her first research
experience w a s in the Physics D e p a r t m e n t
at U W O in 1 9 7 2 , w h e n the first-year
p h y s i c s lab i n s t r u c t o r , Pat C h e f u r k a , hired
M a r y A n n e as a s u m m e r research assistant
t o w o r k on Langmuir-Blodgett f i l m s . It w a s
this t a s t e of research, along w i t h a love for
teaching, that d e t e r m i n e d M a r y A n n e ' s
career path.
Supported by an NSERC 1 9 6 7 Science and
Engineering
Scholarship,
Mary
Anne
studied for her PhD w i t h the late J i m
M o r r i s o n , w h o w a s t h e n Director of t h e
Institute
for
Materials
Research
at
M c M a s t e r U n i v e r s i t y . A l t h o u g h J i m taught
c h e m i s t r y at M c M a s t e r , he supervised b o t h
c h e m i s t r y and physics s t u d e n t s , and his
lab w a s located in t h e p h y s i c s w i n g .
In
addition, w i t h o u t k n o w i n g their addresses,
it w a s d i f f i c u l t t o guess w h e t h e r the
(many) v i s i t o r s t o the lab w e r e p h y s i c i s t s
or c h e m i s t s . This a t m o s p h e r e provided an
excellent
introduction
to
first-class
research w i t h o u t labelling it " p h y s i c s " or
" c h e m i s t r y " . M a r y A n n e ' s PhD thesis title
was
" O r i e n t a t i o n a l Ordering in Solid
M e t h a n e at L o w T e m p e r a t u r e s " .
In 1 9 7 9 , M a r y A n n e w a s a w a r d e d an
NSERC Postdoctoral F e l l o w s h i p , and she
used the o p p o r t u n i t y t o spend t w o years at
O x f o r d U n i v e r s i t y , s p l i t t i n g her t i m e
b e t w e e n c a l o r i m e t r i c studies w i t h Lionel
Staveley
in the Inorganic
Chemistry
Laboratory, and n e u t r o n s c a t t e r i n g studies
w i t h J o h n W h i t e ( w h o w a s t h e n Director
of l ' I n s t i t u t Laue-Langevin, Grenoble). In
addition,
Mary Anne
held a Junior
Research F e l l o w s h i p at St. Hilda's College,
providing her first (and v e r y interesting)
experience w i t h a w o m e n - o n l y educational
institution.
In 1 9 8 1 , NSERC smiled on M a r y A n n e
again, and she w a s a w a r d e d an NSERC
U n i v e r s i t y Research Fellowship, w h i c h she
initially took up as an A s s i s t a n t Professor
(Research) at U n i v e r s i t y of W a t e r l o o .
In
1 9 8 3 , w i t h the o f f e r of a tenure-track
position, M a r y A n n e m o v e d the NSERC
URF t o Dalhousie U n i v e r s i t y in Halifax,
w h e r e she has risen t h r o u g h the ranks t o
the present position of Professor of
C h e m i s t r y and Professor of Physics.
A l t h o u g h M a r y A n n e teaches only in
C h e m i s t r y , she has had research s t u d e n t s
f r o m both C h e m i s t r y and Physics.
Like m o s t professors, M a r y A n n e ' s w o r k
involves a balance of teaching, research
and a d m i n i s t r a t i o n . Not only does M a r y
A n n e enjoy t e a c h i n g and research, but she
has received several recent recognitions
for these aspects for her w o r k , notably the
Faculty of Science A w a r d for Excellence in
Teaching ( 1 9 9 3 ) , the A l u m n i A s s o c i a t i o n
A w a r d for Teaching Excellence ( 1 9 9 3 ) , the
Stig Sunner M e m o r i a l A w a r d of the
C a l o r i m e t r y Conference ( 1 9 9 4 ) and the
Noranda A w a r d of the Canadian Society
for c h e m i s t r y ( 1 9 9 6 ) .
In 1 9 9 1 , M a r y
Anne
visited
11
Canadian
Physics
D e p a r t m e n t s as a CAP lecturer, presenting
a lecture "Properties of M a t t e r : From
Fudge to P h o t o c o p y i n g " .
M a r y A n n e ' s area of research is t h e r m a l
properties of materials, especially solids
w i t h w e a k orientational f o r c e s w h e r e
d y n a m i c a l disorder is possible. She leads
an e x p e r i m e n t a l e f f o r t in w h i c h the
approach is m e a s u r e m e n t of t h e r m a l (and
related) properties of solids, usually w i t h
c u s t o m - d e s i g n e d apparatus, in order to
understand
fundamental
processes
governing
such
matters
as
heat
conduction,
polymorphism,
and
thermodynamic stability.
The s y s t e m s
studied have been c h o s e n t o
probe
particular
intermolecular
interactions:
inclusion c o m p o u n d s have been very
useful in this regard, leading t o a general
u n d e r s t a n d i n g of
heat c o n d u c t i o n
in
molecular s y s t e m s w h i c h is quite d i f f e r e n t
f r o m the " t e x t b o o k " cases of simple solids.
(Optic modes play i m p o r t a n t roles in
molecular
materials).
The w o r k
is
" c h e m i s t r y " in t h e sense that the s y s t e m s
studied are m o s t l y molecular, but m o s t of
the m e a s u r e m e n t s can be called " p h y s i c s "
if y o u adhere t o the old adage t h a t v a c u u m
lines d i s t i n g u i s h the fields (metal for
p h y s i c i s t s , glass for c h e m i s t s ) .
At present M a r y A n n e has f i v e s t u d e n t s in
her research g r o u p - t w o PhD s t u d e n t s ,
t w o M S c s t u d e n t s and one honours project
student.
Four s t u d e n t s have c o m p l e t e
PhD's in her group, and one student has
c o m p l e t e d an M S c . Of those c o m p l e t e d ,
all are e m p l o y e d in the U S A .
Of the
c h e m i s t s , t w o hold positions at universities
and t w o
are in the
pharmaceutical
industry. The physics PhD has c h o s e n t o
apply his excellent e x p e r i m e n t a l and
theoretical skills in the field of medical
physics.
M o s t of the w o r k in M a r y A n n e ' s lab is
supported by NSERC t h r o u g h research
g r a n t s . She has also held c o n t r a c t s or g r a n t s
f r o m N A T O ; Stelco; E.I. DuPont; Energy,
M i n e s and R e s o u r c e s ; S . C . J o h n s o n ;
Canadian Industrial Innovât ion Cent re. M a r y
A n n e has been author or co-author of more
t h a n 7 0 research papers and one book
chapter. In addition, she is just c o m p l e t i n g a
t e x t b o o k ( w o r k i n g t i t l e : " P r o p e r t i e s of
M a t e r i a l s " ) for a materials science class
w h i c h she has developed.
On the personal side, M a r y A n n e is married
t o Robert W h i t e . A l t h o u g h t h e y m e t w h e n
t h e y w e r e b o t h graduate s t u d e n t s in
c h e m i s t r y at M c M a s t e r , t h e y really got to
k n o w each other on the baseball field (Rob
w a s the c a p t a i n of the organic c h e m i s t r y
t e a m , and M a r y A n n e - being a physical
c h e m i s t - w a s the t e a m statistician). Rob
is also a f a c u l t y m e m b e r at Dalhousie
U n i v e r s i t y . Their research areas are q u i t e
far apart (Rob is a biological chemist) and
t h e y have never y e t managed a laboratory
collaboration (those biological s y s t e m s
require t o o high t e m p e r a t u r e s for M a r y
A n n e ' s cryogenic interests!), but t h e y have
collaborated on t w o children - David (b.
1 9 8 2 ) and A l i c e (b. 1 9 8 5 ) .
Outside of teaching, research and f a m i l y ,
M a r y A n n e is interested in music and also
in bringing science t o the general public.
W i t h several o t h e r s she helped open
D i s c o v e r y Centre, an i n t e r a c t i v e science
centre in Halifax.
She also has been
involved w i t h D i s c o v e r y Channel (she had
a spot called " H o w Things W o r k " in their
inaugural season), c l a s s r o o m v i s i t s and
radio (e.g. Quirks & Quarks). A l t o g e t h e r ,
she has a v e r y full and f u n life!
119
MARRIED T O A FELLOW PHYSICIST, 2 0 0 0 MILES A W A Y
by
A n n a Hayes and Stephen Sterbenz
The f a m i l y profile of a p h y s i c s couple
m i g h t s e e m a mundane subject t o f e a t u r e
in a journal. A s one friend put it, " y o u
d o n ' t really w a n t t o tell about any of the
interesting s t u f f and the rest nobody cares
about".
Nonetheless, w e decided t o
accept the i n v i t a t i o n t o produce a profile,
encouraged partially by the hope that it
might help raise a w a r e n e s s of s o m e of the
issues facing physics couples.
The major d i f f e r e n c e b e t w e e n our f a m i l y
and " n o r m a l " f a m i l i e s is t h a t Steve is a
s t a f f m e m b e r at Los A l a m o s National
Laboratory in N e w M e x i c o and I a m a staff
m e m b e r at the Chalk River Laboratories of
AECL in Ontario.
These t w o labs are
about 2 0 0 0 miles apart. Thus, w e find
ourselves running t w o households and
living apart m o s t of the year. W e have
t w o children, M a e v e (7 years old) and
Ciara (2 years old), w h o talk about 'our
house in Candada' and 'our house in
Mos-ahmos'.
Living this odd life s t y l e has been d i f f i c u l t ,
but w e feel t h a t in s o m e sense it w a s
almost inevitable. Dual physics couples
are c o n f r o n t e d w i t h three possibilities: (1)
one of t h e t w o q u i t s p h y s i c s , (2) b o t h stay
in physics but live apart, or (3) t h e y o b t a i n
positions t o g e t h e r (or at least in the same
geographic region!).
S i t u a t i o n (3) is
o b v i o u s l y t h e ideal one. H o w e v e r , it is
also the
most
difficult
to
achieve.
S i t u a t i o n (2) is easier t o arrange t h a n (3),
but of course m u c h harder t o arrange t h a n
(1), since one of the t w o can a l w a y s quit.
Unable so far t o achieve (3), w e have for
n o w made the agonizing choice b e t w e e n
(1) and (2) in f a v o u r of (2).
W e have
e n c o u n t e r e d a w i d e range of opinions on
the w i s d o m of this choice.
A brief h i s t o r y of our careers m a y help
c l a r i f y h o w w e g o t ourselves into the
second of these classes, w o r k i n g n o w at
120
Physics in Canada
M arch/Aprill 9 9 6
opposite ends of the c o n t i n e n t . W e w e r e
graduate students together at Yale at the
n u c l e a r p h y s i c s l a b u n d e r D . Allan Bromley,
and w e got married w h i l e at Yale. Steve is
an experimentalist in nuclear physics and I
a m a t h e o r i s t . A f t e r graduate school w e
maintained s i t u a t i o n (3) for a w h i l e ,
obtaining postdoctoral positions together
at the U n i v e r s i t y of M i n n e s o t a .
From
M i n n e s o t a w e m o v e d t o Los A l a m o s t o
take up our second postdoc positions.
T o w a r d the end of our postdocs at Los
A l a m o s ( 1 9 9 1 ) I w a s o f f e r e d a permanent
position at Chalk River.
Everyone in
nuclear t h e o r y w a s (and still is) finding it
v e r y d i f f i c u l t t o get a permanent position,
and so this seemed quite a stroke of g o o d
f o r t u n e . H o w e v e r , there s i m p l y w a s n ' t a
position at Chalk River for Steve at the
t i m e . Nonetheless, Chalk River being a
large i n s t i t u t i o n , w e had some hope t h a t
things might open up in a year or t w o .
J u s t after I t o o k up m y position at Chalk
River, Steve w a s o f f e r e d a permanent
position at Los A l a m o s . There w a s no
position for me there, but again there
m i g h t be possibilities in a year or t w o ! W e
did not foresee w h a t the j o b c l i m a t e and
research budgets w e r e t o become.
W e w o u l d define ourselves as a v e r y ' 9 0 s
f a m i l y ' - w h i c h means c o m p l i c a t e d . Ciara,
our younger daughter, lives w i t h me in
Canada m o s t of the year, and M a e v e has
just begun t o do extended s t a y s w i t h Dad
in Los A l a m o s . Changing schools h a l f w a y
t h r o u g h the year seems t o be s o m e t h i n g
y o u can get a w a y w i t h w h e n y o u ' r e seven
years old, and M a e v e actually d o e s n ' t
seem t o be u n c o m f o r t a b l e w i t h t h a t . For
me, t h o u g h , t r y i n g t o raise t w o children
alone w h i l e doing physics is no easy task.
I learned q u i c k l y t o change some of m y
parental standards.
For example, being
late for school and eating frozen dinners in
the evening has become part of daily life.
Dressing the children in m a t c h i n g socks is
a thing of the past, but so far w e have no
evidence that our situation has been
harmful to them.
H o w e v e r d i f f i c u l t the logistics of single
parenting, I see that the one living a w a y
f r o m the children has the harder role by
far.
Like all parents, w i t n e s s i n g and
sharing the various milestones our children
pass brings us great j o y .
Hearing by
phone, or even w o r s e , by e-mail or
voice-mail, that your toddler has learned t o
w a l k or t o talk, or that your second grader
can read or is in the school play can really
make you q u e s t i o n w h y y o u ' r e doing
physics 2 0 0 0 miles a w a y . Of course, w e
talk on the phone as a f a m i l y several t i m e s
a w e e k (the phone c o m p a n y loves us), but
w h e n it c o m e s t o t w o - y e a r - o l d children,
the phone is not a particularly g o o d f o r m
of c o m m u n i c a t i o n . In f a c t , half the t i m e
w e ' r e not q u i t e sure if Ciara is even
listening, and the rest of the t i m e w e ' r e
not sure she k n o w s s h e ' s talking w i t h a
person.
That w e have not c h o s e n t o s w i t c h t o the
first of the three o p t i o n s I presented above
for dual career couples reflects the r e w a r d
w e get f r o m physics. The greatest r e w a r d
is probably just that w h i c h every physicist
feels w h o has the l u x u r y of being paid t o
do w h a t he/she loves t o do. W e b o t h
agree that physics has been a g o o d career
choice in t e r m s of on-the-job s a t i s f a c t i o n .
Furthermore, being married t o a f e l l o w
physicist has had some advantages. One
of these is having someone t o w h o m y o u
can
ask
that
dumb
question
that
y o u ' r e t o o embarrassed t o admit y o u r
c o n f u s i o n on t o anyone else. W e probably
engage in more shop-talk t h a n even the
average physics couple, since w e share the
same subfield.
The e x p e r i m e n t a l v s .
theoretical split in the f a m i l y helps t o keep
egos under control. In f a c t , w e published
a c o m m e n t in Phys. Rev. together recently.
A n o t h e r advantage is t h a t w e tend t o
k n o w about t w i c e as m a n y people in
physics as w e o t h e r w i s e m i g h t , and s o m e
of these c o n n e c t i o n s have lead t o fertile
collaborations.
A large f r a c t i o n of our conversations
c o n c e r n physics. The f r a c t i o n probably
crosses the 5 0 % m a r g i n if y o u include
physics gossip! Daughter M a e v e recently
provided an interesting c o m m e n t about
this.
Steve f o u n d himself lacking a
babysitter one Saturday and ended up
taking M a e v e t o sit at t h e back of the
m e e t i n g r o o m at a physics conference.
W h e n I asked her later w h a t she t h o u g h t ,
she said that it w a s no d i f f e r e n t t h a n the
usual c o n v e r s a t i o n s M o m and Dad get
into, especially w h e n w e have our friends
over.
I think i t ' s fair t o say that the details of our
careers are not particularly significant
w h e n it c o m e s t o explaining h o w it is t h a t
w e find ourselves w o r k i n g at d i f f e r e n t
institutions. This is because in the present
j o b c l i m a t e it is unrealistic for m o s t couples
t o expect t o find positions together. A t
the same t i m e , the 1 9 9 0 AIP s u r v e y of
m e m b e r s of the A m e r i c a n Physical Society
s h o w s that
about
70%
of
women
members are married t o another s c i e n t i s t .
It's w o r t h noting, h o w e v e r , that the same
survey f o u n d t h a t " w o m e n do not appear
t o be in f a v o u r of special c o n s i d e r a t i o n ;
m o s t of t h e m s i m p l y w a n t the barriers to
their success r e m o v e d " . I subscribe t o this
point of v i e w m y s e l f .
A barrier that some w o m e n have faced
involves opinions held by some other
p h y s i c i s t s on the issue of
possible
pregnancy or m a t e r n i t y leave and its
bearing on a w o m a n ' s a p p l i c a t i o n for a j o b
or a f e l l o w s h i p .
The q u e s t i o n of h o w
pregnancy
might
affect
our
job
performance
has
never
been
raised
explicitly w i t h us by any
employer.
H o w e v e r , b o t h of our d a u g h t e r s w e r e born
during frantic and critical t i m e s in our
careers and w e w e r e v e r y c o n c e r n e d about
this issue.
In f a c t , in c o n n e c t i o n w i t h
M a e v e ' s b i r t h ( w h i l e w e w e r e at U.
M i n n e s o t a ) , I spent not more t h a n about
three w e e k s a w a y f r o m w o r k , t h a n k s
largely t o m y s i s t e r ' s being able t o c o m e
over f r o m Ireland and act as nanny for a
while.
Perhaps the trickiest obstacle w e have met
at j o b i n t e r v i e w s is the grilling t o w h i c h w e
are generally s u b j e c t e d o n the issue of t h e
'trailing s p o u s e ' . This arises because m o s t
potential e m p l o y e r s d o not w a n t to make
a j o b o f f e r to s o m e o n e w h o m a y t u r n the
o f f e r d o w n because his or her spouse c a n ' t
find a job at the same i n s t i t u t i o n . In all j o b
i n t e r v i e w s , w e tried to make it clear that
w e w e r e not asking for t w o j o b s , because
w e felt that our probability of success in a
close-coupling
arrangement
was
d r a m a t i c a l l y d i m i n i s h e d . Nonetheless, at
one u n i v e r s i t y , w e d i s c o v e r e d indirectly
and long after m y i n t e r v i e w that a l t h o u g h
I w a s the t o p candidate, I w a s not o f f e r e d
the j o b because I w a s m a r r i e d t o a
p h y s i c i s t . Eventually, the p r o b l e m s that
this issue raised at j o b i n t e r v i e w s b e c a m e
so serious and f r u s t r a t i n g that w e thought
of circulating a r u m o u r that w e w e r e about
t q get a d i v o r c e !
In s u r v e y i n g s o m e male p h y s i c i s t s w h o s e
spouses are not p h y s i c i s t s , w e f o u n d t h a t
in general t h e y w e r e not asked t o spend
significant t i m e d i s c u s s i n g their spouses
d u r i n g j o b i n t e r v i e w s . In our opinion, this
m a l e / f e m a l e a s y m m e t r y is unfair. W e feel
that the best candidate should be o f f e r e d
the job and t h a t couples should be g i v e n
the o p p o r t u n i t y t o decide for t h e m s e l v e s
w h e t h e r or not t h e y w a n t to chose the
second of the three o p t i o n s . W e recognize
that this policy may have d i f f i c u l t practical
i m p l i c a t i o n s for u n i v e r s i t y d e p a r t m e n t s and
l a b o r a t o r y a d m i n i s t r a t o r s , but w o u l d ask
t h e m to consider the far more p r o f o u n d
i m p l i c a t i o n s for people like us. M a k i n g an
o f f e r on merit alone makes the selection
clearer and easier, and little real harm is
done.
If the candidate does chose to
decline the o f f e r because of the s p o u s e ' s
lack of an o f f e r , t h e n the i n s t i t u t i o n can
still m a k e an o f f e r t o the runner-up if the
decision is d e m a n d e d in a t i m e l y fashion.
Since setting up our t w o separate homes
in 1 9 9 1 , w e have managed t o live together
as a f a m i l y for an e x t e n d e d period only
w h e n Ciara w a s born. A b o u t a m o n t h
before the birth, Steve took f a m i l y leave
f r o m Los A l a m o s . During this m o n t h w e
b o t h w o r k e d at Chalk River, Steve keeping
up w i t h things back in Los A l a m o s but also
helping o n a volunteer basis in an
e x p e r i m e n t here. A f t e r Ciara w a s born I
t o o k m a t e r n i t y leave f r o m Chalk River and
m o v e d to Los A l a m o s . Being a physics
f a n a t i c , I used m y leave as a " s a b b a t i c a l "
at Los A l a m o s , and so w e lived as a
' n o r m a l ' f a m i l y in s i t u a t i o n (3). I w o r k e d
essentially full-time in the theoretical
d i v i s i o n at Los A l a m o s , w h o
kindly
provided me an o f f i c e and c o m p u t a t i o n a l
facilities but no salary or expenses. From
a physics point of v i e w this w a s a g o o d
year, and I w a s able to use the o p p o r t u n i t y
t o get i n v o l v e d in n e w collaborations.
H o w e v e r , m y d r i v e t o do physics did cost
us m a n y t h o u s a n d s of dollars in d a y c a r e
expenses. The l u x u r y of living together as
a f a m i l y and w o r k i n g full-time in physics
seemed w o r t h the c o s t .
Our careers have been very r e w a r d i n g and
s u c c e s s f u l for us as individuals. Steve is
n o w managing a very large program at Los
A l a m o s , and I feel I have achieved
reasonable recognition in m y field, but
these successes have c o m e only w i t h
great sacrifice.
The overall s i t u a t i o n ,
i n v o l v i n g f a m i l y trips as f r e q u e n t l y as can
be arranged (about every six w e e k s t o t w o
m o n t h s ) , has been bearable, but only by a
small m a r g i n . M a e v e enjoys a v e r y g o o d
relationship w i t h Dad w h i c h m a y have
been developed in part as a result of our
unusual lifestyle. She appears t o accept
our s i t u a t i o n w i t h only minor c o m p l a i n t
and is p r e t t y m u c h a happy kid. Ciara is
too y o u n g t o express her feelings in the
f o r m of a c o m p l a i n t . She talks about Dad
a lot, but b e t w e e n visits she s o m e t i m e s
seems even to forget w h a t ho looks like.
W e h a v e n ' t f o u n d the u l t i m a t e s o l u t i o n t o
our problematic situation. In f a c t , I d o not
k n o w w h e t h e r there is a perfect s o l u t i o n to
the o b v i o u s problem that w e and m o s t
other physics couples face. But w e still
remain hopeful t h a t , in our case, it is
s o m e h o w just around the c o r n e r .
DIRECTORY OF WOMEN
PHYSICISTS
The CAP is currently updating its Directory of
Women Physicists and invites all w o m e n physicists
to register in this Directory.
For information/registration form please contact
the CAP office at
Suite 112, McDonald Building,
1 5 0 Louis Pasteur,
Ottawa, Ontario K1N 6N5
Tel.: 6 1 3 5 6 2 - 5 6 1 4 ; Fax: 6 1 3 5 6 2 - 5 6 1 5 ;
Email CAP@ Physics.uottawa.ca.
121
P H Y S I C S F A M I L Y PROFILE:
J O H N BERLINSKY A N D C A T H E R I N E KALLIN
W e are delighted t o have the o p p o r t u n i t y
t o w r i t e for Physics in Canada about our
experiences as a " p h y s i c s c o u p l e . " This
t y p e of article is useful for a number of
reasons. On the one hand, it d o c u m e n t s
s o m e of the internal barriers w h i c h are
built into the a c a d e m i c / r e s e a r c h s y s t e m
and w h i c h are more or less invisible t o
e v e r y o n e e x c e p t those w h o are d i r e c t l y
affected.
A t t h e same t i m e , it a l l o w s
t h o s e of us w h o are in this s i t u a t i o n t o
" c o m p a r e n o t e s " . In our experience, t h i s
t y p e of c o m p a r i s o n f r e q u e n t l y reveals a
surprising c o n s i s t e n c y and recurrence of
similar experiences. For these reasons w e
hope that our c o n t r i b u t i o n t o this c o l l e c t i o n
of articles w i l l be useful and interesting to
other present or p r o s p e c t i v e
physics
couples and also t o their colleagues,
s u p e r v i s o r s and a d m i n i s t r a t o r s .
H o w w e first got t o g e t h e r as a physics
couple is a long and (for us) interesting
s t o r y w h i c h w e have decided t o defer to
our m e m o i r s . The m o s t n o t e w o r t h y event
for the purpose of this article is that w e
w e r e married in M a y 1 9 8 3 at a small,
private c e r e m o n y in W e s t Point Grey,
Vancouver.
Catherine w a s t h e n a grad
s t u d e n t in her third year at Harvard, and I
w a s an established, i.e. tenured, Physics
f a c u l t y m e m b e r at UBC. A t t h e t i m e of
our marriage, Catherine w a s spending the
semester at the Institute for Theoretical
Physics (ITP) at UC Santa Barbara, w h e r e
her Ph.D. thesis supervisor, Bert Halperin,
w a s o n sabbatical.
W h e n w e returned
there and announced our n e w status at
lunch on t h e Santa Barbara pier, Bert first
chastised Catherine for m a k i n g s u c h an
i m p o r t a n t m o v e w i t h o u t c o n s u l t i n g her
supervisor and t h e n ordered a round of
c h a m p a g n e t o celebrate.
The f o l l o w i n g year Catherine c o m p l e t e d
her thesis o n c y c l o t r o n resonance and
e l e c t r o n - e l e c t r o n interactions in the t w o d i m e n s i o n a l e l e c t r o n gas. A t that t i m e the
f r a c t i o n a l q u a n t u m Hall e f f e c t w a s a hot
topic and her thesis w o r k w a s a useful
contribution
toward
understanding
122
Physics in Canada
M arch/Aprill 9 9 6
e x c i t a t i o n s f r o m the FQHE state. In the
Fall before g r a d u a t i o n , like any other
finishing graduate student, she sent out a
number of letters applying for postd o c t o r a l positions and t h e n w a i t e d . Being
Canadian she also applied t o NSERC w h i c h
had generously supported her graduate
w o r k . A s f r e q u e n t l y happens, she t h e n
spent m o n t h s biting her nails, w a i t i n g for
replies, t h e n had one day of pure e c s t a s y
w h e n the first o f f e r letter arrived, and next
w a s plunged into c o n f u s i o n w i t h the arrival
of the second o f f e r . The t w o key o f f e r s
happened to c o m e f r o m t w o Nobel prize
w i n n e r s w h o w e r e k n o w n to be s o m e w h a t
c o m p e t i t i v e . The m a t t e r of w h i c h o f f e r t o
accept loomed as a decision w h i c h could
just as easily end a career as start one. In
the end, d i p l o m a c y paid off and Catherine
emerged unscathed. Fortunately she still
considers b o t h prospective e m p l o y e r s t o
be friends.
The decision w a s t o accept an o f f e r f r o m
the ITP in Santa Barbara w h e r e the
Director w a s the Condensed
Matter
theorist,
Bob Schrieffer.
Not
long
a f t e r w a r d , NSERC c a m e t h r o u g h w i t h a
post-doctoral f e l l o w s h i p , w h i c h w e used to
negotiate an agreement w i t h Santa Barbara
and UBC so that Catherine could spend
several m o n t h s each year w o r k i n g in
V a n c o u v e r . This agreement turned out t o
be particularly i m p o r t a n t the f o l l o w i n g year
w h e n our daughter w a s born.
The
t r a n s i t i o n f r o m grad school t o post-doc
changed a trans-continental c o m m u t e into
a short N o r t h - S o u t h hop.
A l s o the
d i f f e r e n c e b e t w e e n graduate and post-doc
salaries w a s enough t o cover our phone
bills and t o a l l o w me t o pay off the line of
credit
which
had
been
steadily
a c c u m u l a t i n g at the bank.
The ITP w a s a lively pace in 1 9 8 4 / 8 5 and
q u i t e hospitable t o a y o u n g c o m m u t i n g
couple. W e met a g e n e r a t i o n of post-docs
w h o are n o w professors scattered across
N o r t h A m e r i c a and grad s t u d e n t s w h o are
w o r k i n g their w a y t h r o u g h the ranks. One
physics couple, w h o w e did not even
realise w e r e a couple, w e r e secretly
married w i t h a child being raised by
g r a n d p a r e n t s in England. It w a s a g o o d
surprise t o everyone w h e n w e w e r e invited
t o a party w h e r e this w a s announced.
Steve Kivelson, n o w at U C L A , and Daniel
A r o v a s , n o w at La Jolla, w o r k e d w i t h
Catherine and Bob Schrieffer on the
" c o r r e l a t e d ring e x c h a n g e " t h e o r y of the
FQHE, an original and intuitive alternative
w a y of looking at Laughlin's
wave
f u n c t i o n , and I garnered thousands of
frequent flier miles w i t h W e s t e r n Airlines,
w h i c h finally earned me a free t i c k e t that
I w a s never able t o use because it arrived
as w e w e r e leaving California.
Most
important of all, h o w e v e r , w a s
the
u n e x p e c t e d but w e l c o m e realization that
w e w e r e f a t e d to b e c o m e parents.
This w a s w h e r e the flexible arrangement
w i t h ITP and UBC paid o f f . I rented a
small house on a large lot in the Dunbar
area of V a n c o u v e r , and Catherine m o v e d
up at the beginning of A u g u s t 1 9 8 5 , w i t h
the understanding that she w o u l d be back
by late December for the last six m o n t h s
of her post-doc at ITP. I had an agreement
w i t h m y d e p a r t m e n t t h a t I w o u l d d o all of
m y teaching in the Fall and t h e n spend the
f o l l o w i n g semester at ITP, and Catherine
w a s g i v e n the o f f i c e of M y e r Bloom w h o
w a s a w a y on research leave. W e also
started t o w o r r y about C a t h e r i n e ' s next j o b
since, w i t h only six m o n t h s left at ITP and
a n e w baby, w e needed t o c u t d o w n on
the c o m m u t i n g . A l m o s t m i r a c u l o u s l y w e
heard that UBC w o u l d be n o m i n a t i n g
someone
for
an
NSERC
University
Research Fellow position.
However we
soon learned t h a t this o p p o r t u n i t y w a s
likely t o be a long shot. W h e n Catherine
approached the Chair of the
hiring
committee,
she w a s
told that
the
d e p a r t m e n t w a s looking for applicants
" . . . w i t h letters f r o m Nobel Laureates," but
that it w a s OK for her t o apply as long as
she w o u l d n ' t be disappointed if she d i d n ' t
get the n o m i n a t i o n .
Our schedule for early September revolved
around c h i l d b i r t h classes, w h i c h
we
attended,
graduate
Stat
Mech
and
undergraduate Q u a n t u m M e c h a n i c s , w h i c h
I w a s teaching, the Physics Colloquium,
w h i c h I w a s organizing, and arranging for
letters f r o m Nobel Laureates. C a t h e r i n e ' s
j o b talk w a s scheduled for September 11,
w h i c h f o r t u i t o u s l y fell on t h e birthday of
our daughter, A n n Berlinsky Kallin (no
hyphen).
Catherine's
talk
on
the
Correlated Ring Exchange Theory of the
Fractional Q u a n t u m
Hall Effect
was
postponed
for
two
weeks.
The
d e p a r t m e n t had great d i f f i c u l t y dealing
w i t h Catherine's application and, in t h e
end, no one w a s nominated. I m m e d i a t e l y
after this decision w a s made, our friend
Steve Girvin arrived to g i v e a c o l l o q u i u m
on the q u a n t u m Hall e f f e c t , and I had the
pleasure of introducing his talk on the day
after v o n Klitzing received the Nobel Prize
for discovering the e f f e c t .
W i t h no j o b prospects at UBC, w e began
scouring the market in earnest.
After
years
of c o m m u t i n g
we
made
the
conscious decision t o market ourselves as
a package.
Wherever w e went w e
i n t e r v i e w e d as a couple w i t h babe in arms.
This led t o m a n y hilarious s i t u a t i o n s , far
more t h a n w e have space t o describe, but
w e did end up rating places on h o w w e l l
they handled the special c i r c u m s t a n c e s of
our i n t e r v i e w s - w h e t h e r t h e y arranged full
schedules of independent i n t e r v i e w s , w h a t
care they provided for A n n , and w h e t h e r
s u f f i c i e n t t i m e w a s a l l o w e d for nursing,
rest, etc. In this regard, the t w o Canadian
universities
where
we
interviewed,
W a t e r l o o and M c M a s t e r , did very w e i l . By
c o n t r a s t , certain California universities
p e r f o r m e d a b y s m a l l y . Not only w e r e they
insensitive t o the logistics of i n t e r v i e w i n g
a couple w i t h an infant, but w e w e r e also
introduced t o reverse n e p o t i s m , and more
t h a n one case of t o k e n i n t e r v i e w s . On the
other
hand, w e
had one
delightful
i n t e r v i e w at a U.S. national w e a p o n s lab,
w h i c h w e w e r e not so interested in, but
w h i c h treated us g r a c i o u s l y , and w e w i l l
a l w a y s cherish the image of A n n w i t h a
s e c u r i t y badge pinned t o her bootie.
U l t i m a t e l y w e w e r e v e r y f o r t u n a t e in
finding positions at M c M a s t e r .
I traded
teaching for a d m i n i s t r a t i o n and t o o k over
the D i r e c t o r s h i p of the Institute
for
Materials Research w h i c h J i m M o r r i s o n , a
c h e m i s t , had just relinquished; and the
Physics D e p a r t m e n t w a s happy t o appoint
Catherine t o a tenure track A s s i s t a n t
Professor position in Condensed M a t t e r
Theory w h i c h t h e y had been t r y i n g t o fill
for over a year. Catherine w a s the first
w o m a n in the physical sciences at
M c M a s t e r , and w e have learned a lot f r o m
t h a t . M u c h of w h a t w e learned has n o w
been i n c o r p o r a t e d
into
a
mentoring
program for junior f a c u l t y in Science and
Engineering w h i c h w a s instigated, at
C a t h e r i n e ' s initiative, t w o years ago.
Having t w o real jobs in H a m i l t o n imposed
an unfamiliar stability on our lives.
We
spent a year finding a large house in
d o w n t o w n H a m i l t o n , w h i c h w e love but
w h i c h w i l l never be w o r t h w h a t w e paid
for it. Of central c o n c e r n w a s child care
for A n n . Our child care in the U.S., w h i c h
had w o r k e d w e l l , c o n s i s t e d , f o r t u i t o u s l y ,
of a s u c c e s s i o n of three w i v e s of male,
Korean physics graduate s t u d e n t s , each of
w h o m had t w o small boys of her o w n .
Our first child care in H a m i l t o n w a s w i t h a
couple w h o t o o k in several children in their
home.
Although
they
came
highly
r e c o m m e n d e d and are still used by other
physics parents, w e f o u n d after a f e w
days that w e w e r e u n c o m f o r t a b l e w i t h
t h e m and q u i c k l y made d i f f e r e n t arrangem e n t s . Having c o m p l e t e c o n f i d e n c e in your
childcare providers is an absolute necessity
for w o r k i n g parents, and even misplaced
apprehension (as ours m a y have been) is
unacceptable. A n e w s p a p e r ad led us t o
Yolanda ( A n n a l w a y s called her " m y
landa"), a y o u n g m o t h e r w i t h t w o small
boys, w h o w a s happy t o care for one child
in her h o m e . Yolanda loved having A n n ,
since she v e r y m u c h w a n t e d a daughter.
By the t i m e t h a t A n n m o v e d on t o day
care, Yolanda had four sons, but still no
daughter.
W e put A n n into day care because Yolanda
and her f a m i l y had m o v e d t o a f a r m in an
o u t l y i n g suburb of H a m i l t o n , and the d r i v e
w a s just too long. M c M a s t e r has t w o day
care centres, one located on the c a m p u s
and one, run by the M c M a s t e r Students
Union ( M S U ) , a f e w blocks off c a m p u s .
W e never experienced the o n - c a m p u s day
care because w e never made it to the t o p
of the w a i t i n g list.
However Ann was
a c c e p t e d into the M S U day care after only
a few weeks.
A l t h o u g h the S t u d e n t s
Union sponsors the day care, the staff and
m a n a g e m e n t are full-time professionals. In
f a c t , w e f o u n d the quality of the care in
this centre to be o u t s t a n d i n g . A n n s t a y e d
there t h r o u g h senior kindergarten.
Preschool child care is designed for the
c o n v e n i e n c e of w o r k i n g parents, but the
school s y s t e m has not yet c o m e t o grips
w i t h the concept of t w o - w o r k i n g - p a r e n t
families.
As
a result
they
start
i n c o n v e n i e n t l y late, end at a t i m e w h e n
most parents have t o be at w o r k , and are
closed on holidays and
"professional
d e v e l o p m e n t d a y s " w h e n e v e r y t h i n g else
is open. In H a m i l t o n , the slack is t a k e n up
by a service called First Base, w h i c h is run
by the Y M C A and w h i c h provides before
and after school child care and day care
w h e n the schools are closed. This w o r k s
w e l l for younger children, but eventually
t h e y o u t g r o w it. W h e n w e realised that
t h a t w a s happening for A n n ( t o w a r d the
end of second grade), w e hired Kathleen
w h o c o m e s to our home every day in t i m e
to meet A n n w h e n she c o m e s home f r o m
school. A f t e r a v e r y short t i m e , w e f o u n d
that Kathleen w a s taking care of us t o o ,
and she has since b e c o m e an indispensable
part of our f a m i l y .
M a n y years ago,
Mildred Dresselhaus of M I T , a m e m b e r of
one of the more f a m o u s physics couples,
advised us that the key t o success for
w o r k i n g couples w a s t o get as m u c h help
as y o u can. (Millie's other t i p for w o m e n
p h y s i c i s t s w a s t o have a good husband.)
M o n e y spent on child care, house care, or
just about any other kind of care that y o u
w o u l d o t h e r w i s e have t o do y o u r s e l f , is
m o n e y w e l l spent.
W e have certainly
f o u n d this t o be the case and have
benefitted greatly f r o m the people w h o
have provided us w i t h these services.
One issue w h c h is closely related to child
care and to balancing f a m i l y and w o r k is
that of travel, w h i c h can range f r o m day
t r i p s , t h r o u g h conferences and c o m m i t t e e
w o r k , t o leaves and sabbaticals. Over the
past t e n years w e have a c c u m u l a t e d
considerable experience w i t h all of these
and more.
A particularly c o m p l i c a t e d
s i t u a t i o n is w h e n b o t h parents have to
travel at the same t i m e independently. In
those cases and in the absence of nearby
g r a n d p a r e n t s , having the possibility of
overnight child care, w h i c h for us w a s
provided by Yolanda and later by Kathleen,
is essential. Of course w h e n b o t h parents
travel t o g e t h e r , it is f r e q u e n t l y possible t o
bring the kid(s) along. W e have done this
many t i m e s - s o m e t i m e s bringing our
sitter, s o m e t i m e s arranging on-site child
care, and s o m e t i m e s just " w i n g i n g it" and A n n actually considers it a perk. She
has particularly enjoyed the w e e k s that w e
have spent over several s u m m e r s at the
A s p e n Center for Physics w h e r e she has
met m a n y other physics kids.
Research leaves and sabbaticals present
d i f f e r e n t problems.
One problem is
coordinating them.
Catherine had t w o
leaves, one for 4 m o n t h s at A T & T Bell
Labs in N e w J e r s e y (paid for in part by her
Sloan Fellowship) and the other for 8
m o n t h s at Cornell w h i c h w a s part of her
first real sabbatical, for w h i c h A n n and I
remained in H a m i l t o n .
Of course w e
visited a lot, and, in the case of Cornell, I
learned that by leaving Ithaca w i t h A n n at
3 : 0 0 a . m . , I could drive back t o H a m i l t o n
in t i m e t o d r o p her off for school. Once, in
1 9 9 1 , w e w e r e able t o coordinate a six
m o n t h leave together w h i c h w e spent at
UBC and w h i c h a l l o w e d me t o resurrect a
long-standing
and
extremely
fruitful
collaboration w i t h W a l t e r Hardy and, in
f a c t , t o bring Catherine into it t o o . Next
year, for the first t i m e , w e w i l l be able t o
take a full year research leave together at
Stanford.
W e are n o w in our 1 0 t h year at M c M a s t e r ,
and w e have had ample t i m e t o reflect on
the barriers and pitfalls w h i c h beset
Physics couples, as w e l l as some of the
benefits. W e k n o w w e have been l u c k y ,
and w e have a great appreciation for the
progress that has been made in m i t i g a t i n g
the s i t u a t i o n s of w o m e n f a c u l t y and
couples. Programs such as parental leave,
w h i c h w e r e not available t o us, are crucial
for m a k i n g academic careers livable for
n e w parents. No m o t h e r should have t o
lecture t w o w e e k s after her c h i l d ' s birth,
nor should one highly qualified m e m b e r of
a couple have to languish in un- or underemployment
because
of
traditional
prejudices about w o m e n or
working
couples. A d e q u a t e child care facilities are
essential for w o r k i n g couples and for single
parents. A variety of t y p e s of child care
are required for d i f f e r e n t stages of the
c h i l d r e n ' s and the parents' d e v e l o p m e n t .
A l t h o u g h there has been m u c h progress in
these m a t t e r s over the past decade, the
w a y has been s l o w and painful, and
flexibility and i m a g i n a t i o n are still essential
tools for survival.
Equally w e l l , the
experience of others can be a useful guide.
The advice that w e received over a decade
ago f r o m Millie Dresselhaus has proven
invaluable for us, and w e hope t h a t some
of the anecdotes in this article w i l l be of
use t o f u t u r e physics couples.
123
P H Y S I C S F A M I L Y PROFILE:
JENIFER A N D M I C H A E L T H E W A L T
W h e n w e w e r e invited t o s u b m i t an article
t o this special issue of Physics in Canada
it w a s impossible for us t o ignore the
o p p o r t u n i t y . Besides being one of the f e w
(two?) married couples in Canada t o hold
faculty
appointments
in
Physics
D e p a r t m e n t s , the guest editor of the issue
is none other t h a n J e n i f e r ' s sister A n n
M c M i l l a n . A n y sense of
professional
responsibility p r o m p t i n g us t o w r i t e the
article has t h u s been magnified e n o r m o u s l y
by sisterly d u t y . A s this is primarily the
s t o r y of J e n i f e r ' s a t t e m p t s t o seek
permanent academic e m p l o y m e n t since the
early 1 9 9 0 ' s , the article w i l l be w r i t t e n
f r o m her p e r s p e c t i v e .
The ' w o m e n ' s
issue' t h i s article w i l l address is that of
targeted
appointments,
in
particular
spousal a p p o i n t m e n t s . M a n y readers m a y
have w e l l - f o r m e d opinions about this issue:
perhaps this article w i l l p r o v o k e s o m e
philosophical reassessments.
a n e w e n v i r o n m e n t , w i t h n e w people, and
e m b a r k i n g on n e w research projects.
A d d e d t o this w a s the inevitable w o r r y
about Eric's well-being:
he w a s looked
after by a lovely and caring y o u n g nanny
during the d a y , but no m a t t e r h o w
e x e m p l a r y the person, changes in childcare
arrangements
are
always
accompanied by some anxiety. Evenings
w e r e fully occupied w i t h Eric, an active
and c a p t i v a t i n g toddler w h o had the habit
of being w a k e f u l b e t w e e n the hours of one
and three a . m . This habit w a s broken out
of necessity shortly after I started w o r k :
M i k e ' s m e m b e r s h i p on the condensed
m a t t e r NSERC grant selection c o m m i t t e e
entailed a w e e k - l o n g sojourn in O t t a w a in
February, during w h i c h I managed t o
c o n v i n c e Eric of the value of u n i n t e r r u p t e d
slumber.
Mike
continued
to
have
tremendous
committee
work
responsibilities during Eric's early years, an
aspect of professorial life he relished
somewhat
less
than
his
research.
Travelling w o u l d take its toll, he o f t e n
returned not only tired but viral, t o be
greeted by a f a t i g u e d 'Physics w i d o w ' w h o
had held the f o r t in his absence.
This unbalanced life-style persisted until a
chance remark by one of
m y UBC
colleagues
raised m y
consciousness.
A s k e d w h e r e Mike w a s , I replied that he
w a s in O t t a w a , serving on the ( n o w
d e f u n c t ) NSERC W o m e n ' s Faculty A w a r d
(WFA)
selection
committee.
This
p r o m p t e d the ironic realization that Mike
w a s helping distribute jobs t o m y peers
w h i l e I w a s 'at home w a t c h i n g the kid'!
The i n v i t a t i o n t o w r i t e this f a m i l y profile
came in t h e s u m m e r of 1 9 9 5 , a t i m e of
considerable t u r m o i l in our careers - I w i l l
elaborate on this later. First, t h o u g h , I w i l l
s u m m a r i z e our personal and professional
b a c k g r o u n d s . Married for 13 years, w e met
in 1 9 8 1 w h e n I w a s a graduate student in
C h e m i s t r y at S i m o n Fraser U n i v e r s i t y and
M i k e w a s a y o u n g A s s i s t a n t Professor of
Physics and NSERC U n i v e r s i t y Research
Fellow. Following a 10-monthcourtship, w e
married the f o l l o w i n g s u m m e r , having
neglected t o d e v e l o p detailed plans for our
f u t u r e careers. M i k e had no real need t o
plan, having already achieved international
recognition in his area of e x p e r i m e n t a l
p h y s i c s : l o w - t e m p e r a t u r e luminescence of
semiconductors. He w o r k e d single-mindedly
and e n t h u s i a s t i c a l l y , developing ever better
s p e c t r o s c o p i c m e t h o d s t o f u r t h e r the
understanding of t h e optical properties of
s e m i c o n d u c t i n g materials. On the other
hand I w a s n o w geographically tethered:
there are just t w o universities in t h e L o w e r
M a i n l a n d of British Columbia. Fortunately,
one of the w o r l d ' s leading research g r o u p s
in m y area, NMR applied t o m e m b r a n e s , is
located in the Physics D e p a r t m e n t at the
U n i v e r s i t y of British C o l u m b i a under the
intellectual umbrella of M y e r
Bloom,
c u r r e n t l y Emeritus Professor. I obtained an
NSERC p o s t d o c t o r a l f e l l o w s h i p t o go across
t o w n f o l l o w i n g m y Ph.D., arrived at UBC
f i v e m o n t h s pregnant, and t o o k advantage
of the m a t e r n i t y leave provisions of the
NSERC a w a r d s t o spend one full year at
h o m e w i t h our son Eric in 1 9 8 8 .
The first years back in the lab w e r e , in
r e t r o s p e c t , challenging ones. Initially there
w a s s o m e i-.security involved w i t h being in
124
O v e r c o m i n g m y natural t e n d e n c y t o finish
e x p e r i m e n t a l studies but leave until an
undefined ' l a t e r ' the w r i t i n g up and
publishing of results, I began t o heave m y
C V out of the d o l d r u m s , w i t h the aim of
eventually applying for a W F A . A gentle
s u g g e s t i o n f r o m M y e r Bloom that I
c o n c e n t r a t e on f o r m i n g links w i t h other
d e p a r t m e n t s , g i v e n m y chequered Physics
past, w a s d u l y noted.
M y pedigree
c o n s i s t s of an undergraduate degree in
Biophysics and a d o c t o r a t e in C h e m i s t r y ,
f o l l o w e d by p o s t d o c t o r a l w o r k in a Physics
lab. Physics d e p a r t m e n t traditionalists still
o f t e n f r o w n on expertise outside 'pure'
Physics, regarding such k n o w l e d g e as
c o n t a m i n a t i n g rather t h a n enhancing a
researcher. Other d e p a r t m e n t s have the
c o m p l e m e n t a r y v i e w , by and large. Since
career advice f r o m M y e r w a s rare (he
prefers
a
non-directive
supervisory
approach), I took it seriously, especially
since interdisciplinary w o r k d o v e t a i l e d w i t h
m y preferences. A fledgling collaboration
w i t h Neil Kitson in the Division of
D e r m a t o l o g y at UBC, s t u d y i n g the physical
properties of skin lipids, w a s nurtured and
gradually began yielding papers.
Neil's encouragement
included
vague
references
to
faculty
positions
in
D e r m a t o l o g y , and the f o l l o w i n g year 1 9 9 3 - I hatched the s c h e m e of creating a
W F A position jointly b e t w e e n Physics and
Medicine at UBC. Neither Mike, w h o s e lab
w a s by n o w f u l l y established, and w h o
held an NSERC Industrial Research Chair at
SFU absolving him f r o m teaching for five
years, nor I, w h o loved m y w o r k at UBC
and w h o s e parents live nearby, w a n t e d t o
move away from Vancouver.
However,
creating a position for oneself is never a
s t r a i g h t f o r w a r d process and creating s u c h
a position spanning faculties is even more
d i f f i c u l t . In this case, t h o u g h , the process
w a s facilitated by the Head of the Division
of D e r m a t o l o g y , David McLean, w h o
enthusiastically supports links b e t w e e n
Medicine and 'hard science'.
Similarly
supportive w a s the Head of the Physics
Department at UBC, Brian Turrell, w h o
feels that a Physics approach can be
invaluable for problems outside traditional
Physics, and w h o also feels t h a t the
discipline of Physics can benefit by being
perceived as useful by researchers in other
disciplines. In the s u m m e r of 1 9 9 3 the
Division of D e r m a t o l o g y t o o k the initial
step, in the f o r m of a five-year plan e n t r y
for a m e m b r a n e biophysicist, t o w a r d
creating a position for w h i c h m y skills
w o u l d be ideal.
Under Brian T u r r e l l ' s
direction, the UBC Physics d e p a r t m e n t ' s
Committee
on
Initial
Appointments
evaluated m y W F A research proposal,
solicited letters of reference, asked me t o
give a c o l l o q u i u m and i n t e r v i e w e d me. In
other w o r d s I received fair t r e a t m e n t ,
despite the c o m p l i c a t i o n t h a t UBC had
imposed a hiring freeze w h i c h extended
even t o the subsidized W F A program. This
point, h o w e v e r , became m o o t once the
Physics d e p a r t m e n t discussed w h e t h e r or
not t o s u p p o r t m y W F A n o m i n a t i o n .
Objections w e r e raised because
the
position had not been advertised.
How
one w o u l d go about advertising a position
under a u n i v e r s i t y hiring freeze w a s not
clear, but, nevertheless, the d e p a r t m e n t
decided not t o support the application.
This w a s a disappointing t u r n of events,
but m y n o m i n a t i o n w e n t to O t t a w a
a n y w a y , w i t h the sole support of the UBC
Dept. of Medicine.
Thus ended six w e e k s of the m o s t grueling
e f f o r t I can r e m e m b e r . M i k e had had t w o
w e e k - l o n g trips t o J a p a n during t h a t t i m e ,
and I operated on 3 - 4 hours of
sleep,
hiring baby-sitting in shifts, and becoming
more and more frazzled. The e x c i t e m e n t
of w o r k i n g t o a deadline, and having the
potential t o generate a permanent position,
w a s enough t o sustain this fairly shortt e r m e f f o r t . Over the long t e r m it w o u l d
have been painful t o see the e f f e c t s on
Eric, w h o w a s , no d o u b t , being neglected
by his m o m : small cracks began t o appear
in his d e m e a n o r , his musical education
stopped progressing w i t h the c u s t o m a r y
rapidity, and he seemed generally less
c o n t e n t . This intense w o r k paid off in one
sense h o w e v e r : for Mike it w a s concrete
evidence of m y a m b i t i o n , and he became
more fully appreciative of m y desire for an
academic career.
In J a n u a r y , 1 9 9 4 , the W F A c o m m i t t e e
met.
Mike had tried u n s u c c e s s f u l l y t o
resign f r o m the c o m m i t t e e once it became
clear that m y n o m i n a t i o n w a s on its w a y
t o O t t a w a . This sort of c o m m i t t e e w o r k is
largely t h a n k l e s s :
like the peer r e v i e w
process
it relies on the
continuing
generosity and c o m m u n i t y - m i n d e d n e s s of
scientists in Canada. Mike w a s left in the
a w k w a r d position of standing anxiously
outside in the hall for 2 0 m i n u t e s w h i l e the
c o m m i t t e e d i s c u s s e d m y application. A s a
side remark: the ethics of the c o m m i t t e e
w e r e f l a w l e s s and Mike w a s g i v e n no hint
of the fate of m y application. This rather
inhuman adherence t o the rules w a s m o s t
u n s a t i s f a c t o r y for me - w h i l e Mike w a s in
O t t a w a , I had had the usual single parent
experience made orders of m a g n i t u d e more
unpleasant
by
the
odd
situation.
Psychologically it w a s d i f f i c u l t having m y
spouse in a perceived position of p o w e r
over m y career and there w a s an inevitable
build-up of r e s e n t m e n t as a result. At the
t i m e of m y n o m i n a t i o n I w a s one year
beyond the r e c o m m e n d e d ' t i m e since
Ph.D.' for the W F A a w a r d s , and w a s t h u s
not o v e r l y o p t i m i s t i c about the o u t c o m e .
Six u n c o m f o r t a b l e w e e k s passed before I
heard that I had been u n s u c c e s s f u l , and
even
though
the
news
was
not
u n e x p e c t e d , it w a s still a b l o w .
Selfd o u b t , self-blame and feelings of rejection
w e r e prevalent mental states for some
t i m e f o l l o w i n g the a n n o u n c e m e n t : there
w a s a sense of doors closing p e r m a n e n t l y a f r u s t r a t i n g scenario for me at the age of
3 6 . These feelings w e r e c o m p o u n d e d by
our c o n t i n u i n g failure t o c o n c e i v e a second
child.
The u n a d v e r t i s e d c r e a t i o n of a
position for another y o u n g physicist at
U6C in the late spring w a s a further source
of f r u s t r a t i o n , as w a s the decision by the
UBC Physics d e p a r t m e n t t o advertise for a
W F A position that year. M e a n w h i l e Mike
w a s s u f f e r i n g in s y m p a t h y , and the death
of his father in J u n e c o m p o u n d e d his grief.
In c o n t r a s t , m y research e f f o r t w a s going
w e l l , w i t h the first c o m p r e h e n s i v e papers
f r o m the D e r m a t o l o g y c o l l a b o r a t i o n being
a c c e p t e d for publication, and w i t h an
i n v i t a t i o n t o speak at the annual m e e t i n g
of the C . A . P . in Regina. Mike spoke at the
same m e e t i n g , and for the first t i m e w e
travelled t o g e t h e r on a joint business trip.
I s t a y e d only t w o d a y s , t h e n left t o get
back t o Eric and to s t o p the a c c u m u l a t i o n
of non-deductible extra child-care c o s t s .
It w a s a g o o d trip: I returned feeling a
sense of r e n e w e d energy due t o the
positive c o m m e n t s m y talk had received.
In addition, I had had the chance t o c a t c h
up w i t h m y sister A n n , a l w a y s an
encouraging and u n d e r s t a n d i n g figure.
Later that s u m m e r , Mike, never one to
tolerate s u b - o p t i m a l situations unless g i v e n
no c h o i c e , began considering
career
o p t i o n s for us. A casual c o m m e n t here
and there at SFU regarding m y lack of a
permanent position and the potential
necessity for us t o m o v e a w a y f r o m
V a n c o u v e r began a series of e v e n t s w h o s e
v e l o c i t y and acceleration surprised even
Mike.
I w a s f o r t u n a t e in that m y
interdisciplinary b a c k g r o u n d f i t t e d in w e l l
w i t h Dean of Science Colin J o n e s ' plans to
enhance cross-disciplinary research:
an
a t t r a c t i v e area for graduate s t u d e n t s .
Over the fall m o n t h s of 1 9 9 4 i n f o r m a l
discussions w e r e held a m o n g various
d e p a r t m e n t a l chairs and t h e Dean of
Science
regarding
the
possibility
of
creating a p o s i t i o n for me at SFU. These
discussions led t o a proposal by Colin t o
establish a t a r g e t e d joint a p p o i n t m e n t
b e t w e e n the D e p a r t m e n t of Physics and
the I n s t i t u t e of M o l e c u l a r Biology and
B i o c h e m i s t r y (IMBB).
This w a s not a
decision that w a s made casually:
there
w a s e x t e n s i v e d i s c u s s i o n in the Physics
D e p a r t m e n t about the situation.
Prof.
Frindt, d e p a r t m e n t chair, sent a m e m o t o
his f a c u l t y advising t h e m of the problem,
emphasizing M i k e ' s central role in the
d e p a r t m e n t ' s success in raising research
f u n d s , and outlining m y
background,
appending m y W F A research proposal and
the external r e v i e w s thereof. The Dean
met w i t h the D e p a r t m e n t of Physics as a
w h o l e t o discuss the establishment of the
joint a p p o i n t m e n t and also held discussions
w i t h the Director of the IMBB. By secret
ballot in w h i c h M i k e did not participate, a
decision w a s made in f a v o u r of pursuing
the idea of creating a position for w h i c h I
w o u l d be considered. The decision w a s
not u n a n i m o u s :
some m e m b e r s of the
d e p a r t m e n t felt that the exercise w a s one
in w h i c h p r a g m a t i s m w a s c o m p l e t e l y
outweighing 'principle'.
In the end, the
d e p a r t m e n t made the courageous choice t o
proceed w i t h their e v a l u a t i o n of me, clearly
labelling the potential job a spousal
appointment.
An appointments committee w a s formed
at this stage, letters of reference w e r e
solicited in the usual manner, and I w a s
i n t e r v i e w e d on M a y 1, 1 9 9 5 by b o t h the
Physics D e p a r t m e n t and the IMBB. The
i n t e r v i e w did not feel in any w a y w a t e r e d
d o w n due t o the ' s p o u s a l ' nature of the
position: I presented t w o one-hour talks,
a teaching d e m o n s t r a t i o n and a research
seminar, met w i t h m e m b e r s of both
departments,
and
was
thoroughly
e x h a u s t e d at the end of the d a y . M o n d a y
M a y 1st w a s also the deadline for NSERC
Collaborative Project Grant proposals t o
arrive in O t t a w a , and I had been busy up
until the Friday before p u t t i n g the finishing
t o u c h e s on a grant application.
(This
process w a s a little f r u s t r a t i n g since I had
d i s c o v e r e d rather late that I w a s ineligible
t o apply for s u c h a grant due to m y lack at
t h a t t i m e of a f i r m o f f e r of a p p o i n t m e n t the application instead w a s s u b m i t t e d in
the names of m y collaborators.)
T i m e passed, as one m e m b e r of the
appointments
committee
was
away.
W h e n the c o m m i t t e e m e m b e r s
were
reunited,
they
wrote
a
report
r e c o m m e n d i n g me for the position. The
members
of
the
IMBB
had
voted
unanimously
in
favour
a
muchappreciated v o t e of c o n f i d e n c e .
Finally,
the Physics D e p a r t m e n t r a t i f i c a t i o n v o t e
w a s held, and achieved in excess of the
required t w o - t h i r d s m a j o r i t y . SFU's Board
of Governors approved m y a p p o i n t m e n t in
late J u l y , and m y e m p l o y m e n t c o n t r a c t
w a s signed soon a f t e r .
This w o u l d
normally signal the ' H a p p y Ending' of this
article.
Instead, e v e n t s took a t u r n into the arena
of academic pulp f i c t i o n . One day in midAugust, while I w a s making measurements
at UBC, one of m y colleagues c a m e in and
t o o k me aside. He told me that he had
heard that I had been the subject of a talk
radio program that morning. Stunned, I
inquired f u r t h e r , and w a s told t h a t a
particular retired SFU Physics professor
had taken his 'principled' objections t o m y
a p p o i n t m e n t t o the a i r w a v e s . M y name
had been mentioned, along w i t h M i k e ' s . A
f e w phone calls t u r n e d up a c o p y of the
tape, w h i c h I listened to that night.
Factually c o r r e c t but highly selective in
c o n t e n t , the i n t e r v i e w w a s insulting and
biased. For e x a m p l e , t h r o u g h o u t I w a s
referred t o as ' M r s . T h e w a l t ' - certainly not
the appropriate title t o use in m a t t e r s
relating to m y career. Resisting the urge
t o respond t o this attack on S F U ' s
character, I tried t o forget that the incident
had happened.
I w a s able t o do this
easily, as I w a s preparing t o g i v e an invited
talk at a Gordon Conference the f o l l o w i n g
week.
The day before I left for the
conference,
h o w e v e r , I happened
to
encounter an acquaintance w h o had heard
the radio s h o w but w h o had not c o n n e c t e d
me w i t h the c o n t e n t : e m b a r r a s s m e n t of
b o t h parties w a s kept t o a m i n i m u m , but
m y anger level increased as I realised that
m y n e w l y - m i n t e d public r e p u t a t i o n w a s
significantly less f l a t t e r i n g t h a n I w o u l d
have preferred. Over the next f e w w e e k s
there w a s a f l u r r y of media articles in the
local papers concerning m y
spousal
a p p o i n t m e n t . The headline 'SFU Denies
N e p o t i s m ' enhanced the v o c a b u l a r y of the
local t a b l o i d ' s readership at the same t i m e
as it gave u n w a r r a n t e d negative publicity
to the u n i v e r s i t y . Finally, the u n i v e r s i t y
papers w r o t e their pieces about the issue,
and the dust settled.
Emotional fall-out takes more t i m e , but
w h e n I t o o k up m y a p p o i n t m e n t in
September
I felt
generally
warmly
welcomed
and c o m f o r t a b l e .
Notice
received in October t h a t the collaborative
grant had been a w a r d e d w a s
most
w e l c o m e , and gave me a greater sense of
a u t o n o m y , as did m y recent a p p o i n t m e n t
as A d j u n c t Professor of Medicine at UBC.
Myer Bloom has continued t o be an
i m p o r t a n t source of s u p p o r t , and Mike has
managed t o navigate the minefield of
playing the dual roles of husband and
colleague w i t h admirable d e x t e r i t y . A s far
as being a t w o - c a r e e r f a m i l y goes, I feel
exceptionally f o r t u n a t e in t w o respects:
M i k e ' s preferred m e t h o d of relaxation after
w o r k involves c o o k i n g , and Eric's live-in
nanny, Petra Persch, is w i t h o u t peer.
The current over-supply of highly qualified
people searching for u n i v e r s i t y f a c u l t y
positions at a t i m e w h e n
university
budgets are being reduced is regrettable
and resentment of holders of targeted
a p p o i n t m e n t s of one kind or another is
inevitable. In an ideal w o r l d , no-one w o u l d
be u n d e r - e m p l o y e d . Spousal a p p o i n t m e n t s
are not a n e w phenomenon. Our s i t u a t i o n
w a s unusual in t h a t Mike already had a
position w h e n m y spousal a p p o i n t m e n t
w a s created, but the end result is identical.
Again, in an ideal w o r l d , jobs suiting b o t h
partners in a marriage w o u l d
exist
automatically
within
a
confined
geographical area. This is o b v i o u s l y an
impossible w i s h . Some might say t h a t one
partner should sacrifice their career for the
o t h e r ' s , and in fact w e feel that I have
done this in the past t o some e x t e n t ,
although ' s a c r i f i c e ' is t o o strong a w o r d .
Certainly, the c o m b i n a t i o n of academic
career and child-rearing is challenging for
both parents. In our case, w e feel t h a t the
s l o w e r start t o m y career, w h i c h w i l l
inevitably have a big impact on m y l i f e t i m e
earnings, is a reasonable price t o pay for
the lifetime privilege of having children.
125
M O V E B E Y O N D T H E U N C E R T / J N T Y PRINCIPLE IN F A M I L Y A N t ) CAREER
by
Ying Qi, A t m o s p h e r i c Environment Service, 4 9 0 5 D u f f e r i n St., D o w n s v i e w , Onta io, M 3 H 5 T 4
tn p h y s i c s and m a t h e m a t i c s , there is a
w e l l - k n o w n u n c e r t a i n t y principle, w h i c h
says " t h e precise m e a s u r e m e n t s of t i m e
and
frequency
are
fundamentally
i n c o m p a t i b l e , since f r e q u e n c y c a n n o t be
measured i n s t a n t a n e o u s l y " .
In our life,
career and f a m i l y , particularly for a
w o m a n , are o f t e n in c o n f l i c t w i t h each
other. A career w o m a n m a y be successful
at a c o s t t o her f a m i l y life. In this sense,
f a m i l y and career seem also t o observe the
u n c e r t a i n t y principle.
It is hard for a
w o m a n t o have b o t h of t h e m in perfect
harmony!
I a m an a t m o s p h e r i c scientist and n o w
w o r k at A t m o s p h e r i c Environment Service
(AES), Environment Canada as a c o n t r a c t
research s c i e n t i s t . I have a simple f a m i l y ,
m y husband J i n g n a n Zhou and me.
My
husband is also an a t m o s p h e r i c scientist
and n o w w o r k s as a research assistant at
the D e p a r t m e n t of Earth and A t m o s p h e r i c
Science, York U n i v e r s i t y . A c t u a l l y , a three
person f a m i l y w o u l d be more exact as w e
w i l l soon have a n e w m e m b e r t o c o m e in
the w o r l d — our u n b o r n baby.
I once
believed in and w a s bound up by the
u n c e r t a i n t y principle in considering career
and f a m i l y , but finally I have m o v e d
beyond the influence of the principle in m y
life.
TO BE A L O N E
Before I met J i n g n a n 8 years ago, I had
decided t o sacrifice m y f a m i l y life t o
develop
my
career
in
atmospheric
sciences. W h e n I w a s a child, I dreamed
of being a great scientist in the w o r l d .
Gradually, I realized t h a t a w o m a n w i t h a
n o r m a l f a m i l y had a v e r y d i f f i c u l t t i m e t o
be successful in her career in science. A s
a m a t t e r of f a c t , m a n y f a m o u s scientists,
not only w o m e n but also m e n are single.
In China, at least half or even more of the
female f e l l o w s of the Chinese A c a d e m y of
Sciences w e r e single before 1 9 8 9 . These
f a c t s reminded me a l w a y s of t h e e x i s t e n c e
of the u n c e r t a i n t y principle for f a m i l y and
career. I did not dare t o expect not t o be
bound by the principle like M r s . Curie ,
because s o m e h o w , I a l w a y s believed in
science m u c h more t h a n in luck.
A n o t h e r reason for m y decision t o sacrifice
m y o w n f a m i l y life t o make m y career
s u c c e s s f u l w a s probably the love of m y
parents, elder sister and brother.
They
a l w a y s supported me t o d e v e l o p m y career
126
Physics in Canada
M arch/Aprill 9 9 6
f a m i l y life. Each t i m e I had a v a c a t i o n ,
t h e y invited me t o go home so sincerely
that I could not t u r n d o w n invitations f r o m
t h e m until I left China t o Canada, even
after I w a s married. They a l w a y s let m e
feel part of the happiest f a m i l y no m a t t e r
w h a t happened. Their love and care made
me feel that I already had a happy f a m i l y .
I w o u l d not regret spending t h e rest of m y
w h o l e life on m y career.
MARRIED
Eight years ago, because of c o m m o n
interest in boundary-layer m e t e o r o l o g y , I
m e t J i n g n a n by chance. He w a s a lecturer
at Nanjing Institute and I w a s a graduate.
J i n g n a n is a person w h o likes t o talk,
particularly in the language of m e t e o r o l o g y .
He loves his career, too.
However,
d i f f e r e n t f r o m me, he also w a n t e d t o
d e v e l o p a f a m i l y not only his career.
Moreover,
he t h o u g h t that
common
interest w a s one of the bases of a happy
f a m i l y in addition t o love, understanding
and care. During each meeting, although
atmospheric science w a s a l w a y s the topic
of the meeting, w e came t o understand
each other more and more
Jingnan's
personality influenced me and reminded me
that I w o u l d lack s o m e t h i n g valuable in m y
life if I kept f o c u s s i n g on m y career.
Finally, I f o u n d our meetings w e r e not only
for meteorological c o n v e r s a t i o n but also a
part of m y life w h i c h could not be lost.
W e g o t married one and half years later.
A f t e r w e w e r e married, w e did not w a n t a
baby as a normal f a m i l y w o u l d because I
w a s still afraid of the u n c e r t a i n t y principle.
H o w e v e r , I w a s not alone any more.
W h e n I w a s a Ph.D graduate at Nanjing
U n i v e r s i t y , Jingnan and I had a chance t o
w o r k in t h e same c o m p u t e r t e r m i n a l room
as he had a cooperative program w i t h
Nanjing U n i v e r s i t y at that t i m e . W h e n I
w a s a p o s t d o c t o r a l f e l l o w at Institute of
M e c h a n i c s , Chinese A c a d e m y of Sciences,
J i n g n a n w a s a visiting researcher at the
same i n s t i t u t e so w e again, had a chance
t o share the same o f f i c e . Frankly, Jingnan
made m u c h more c o n t r i b u t i o n t h a n I did t o
create our small but c o m f o r t a b l e f a m i l y .
Perhaps, in a certain sense, I o w e d him a
lot. W h i l e w e enjoyed our special f a m i l y ,
J i n g n a n got an excellent y o u n g professor
f o u n d a t i o n a w a r d in Jiangsu province. I
got m y Ph.D and published more than 15
papers and 1 book about m y o w n research
achievements.
Shortly after that I w a s
awarded
the
highest
category
of
C h a n g w a n g T u ' s Young Meteorologist
Prize by the Chinese
Meteorological
Society.
MOVE
BEYOND
PRINCIPLE
THE
UNCERTAINTY
In December 1 9 9 3 , I came t o Canada as
an NSERC visiting f e l l o w , accompanied by
J i n g n a n . W e began t o create our n e w
f a m i l y and career e n v i r o n m e n t .
Living
abroad provided us more experience. W e
had more things t o face and t o deal w i t h in
each of our careers w h i l e w e had t o get
used t o the language, f o o d s , e t c . in
Canada as soon as possible. W e examined
again w h e t h e r w e w e r e under control of
the u n c e r t a i n t y principle
A f e w m o n t h s after w e c a m e t o Canada,
Jingnan got a position as a research
assistant at the D e p a r t m e n t of Earth and
A t m o s p h e r i c Science, York U n i v e r s i t y . W e
continued
our
common
interest
in
boundary-layer m e t e o r o l o g y and mesoscale
m e t e o r o l o g y . In the m e a n t i m e , I realized
that it w o u l d be more helpful b o t h t o
Canada and t o m y career if I w o u l d make
a
direct
contribution
to
Canadian
atmospheric research science since I lived
in Canada. Therefore, I f u r t h e r expanded
m y research d o m a i n and developed m y
t w o n e w areas.
One is joining the
research c o m m u n i t y for a n e w Canadian
state-of-the-art mesoscale numerical model
MC2.
The other is exploring
the
applications of a n e w m a t h e m a t i c a l tool,
w a v e l e t analysis, t o meteorological and air
quality research.
The latter is quite a
t h o u g h topic since w a v e l e t analysis is
described
by
modern
functional
m a t h e m a t i c a l language. T o achieve the
objectives, I have not t a k e n any v a c a t i o n s
since I came t o Canada in D e c e m b e r ,
1 9 9 3 . It w a s our happy and relaxed f a m i l y
talk that o f t e n released me f r o m intense
w o r k . W e b o t h enjoy the life style. In the
mingling of intense w o r k and happy f a m i l y
life, I have made some v e r y encouraging
progress in m y n e w research areas. I have
modified and i m p r o v e d one of
the
important schemes in the M C 2 model and
have s u c c e s s f u l l y applied w a v e l e t analysis
in m e t e o r o l o g y and air q u a l i t y research. I
thank Air Quality Research Branch at AES
for supporting m y w o r k after the NSERC
visiting f e l l o w s h i p w a s finished.
Over the past t w o years, w e have
experienced a lot and i m p r o v e d ourselves
a lot, t o o . W e surprisingly f i n d t h a t w e
can really c o m f o r t a b l y balance our careers
and f a m i l y life. Perhaps experience has
g i v e n us the ability. W h a t e v e r , w e have
enough confidence n o w t o start a normal
f a m i l y life during our continued pursuit for
careers in atmospheric sciences. W e are
ready t o w e l c o m e our baby into our lives.
Finally, I realize t h a t I have m o v e d beyond
that u n c e r t a i n t y principle. M o r e o v e r , in a
sense, I feel t h a t the relationship b e t w e e n
a f a m i l y and career seems t o be more like
the relationship b e t w e e n w a t e r and a boat:
w a t e r can carry a boat but w a t e r can also
capsize a boat.
Family life may be in
c o n f l i c t w i t h career, s o m e t i m e s apparently
controlled by the u n c e r t a i n t y principle, but
a happy f a m i l y life can also become a
source of inspiration for o n e ' s career life.
D e v e l o p m e n t of o n e ' s career can t h u s be
greatly
accelerated
because
of
the
existence of a happy f a m i l y .
I should be t h a n k f u l to Jingnan. He makes
me o w n a c o m p l e t e life!
Books Received / Livres
reçus
The f o l l o w i n g books have been received for
r e v i e w . Readers are invited t o w r i t e r e v i e w s ,
in English or French, of books of interest t o
t h e m . Books m a y be requested f r o m the
book r e v i e w editor A n d r é Roberge by email
at a n d r e @ g o l l u m . p h y s . l a u r e n t i a n . c a or at
D e p a r t m e n t of P h y s i c s ,
Laurentian
U n i v e r s i t y , Sudbury, Ontario, P3E 2 C 6 .
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G l i m p s i n g Reality: Ideas in Physics and the
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The Collected W o r k s of P. A . M . Dirac 1 9 2 4
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Lorentzian W o r m h o l e s - From Einstein t o
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Optical-Thermal
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S t r u c t u r a l Electron C r y s t a l l o g r a p h y , by D.L.
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T h e o r y and A p p l i c a t i o n of Laser Chemical
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Book Reviews/
Revues des livres
Riddles in Your T e a c u p , 2nd edition, by
P. Ghose and D. H o m e , I 0 P Publishing,
1 9 9 4 , pp: xiii + 1 7 3 , ISBN 0 - 7 5 0 3 - 0 2 7 5 - 5 ;
Price $ 2 2 U.S. (pbk)
In this revised and enlarged second edition
of Riddles in Your Teacup, the authors,
P. Ghose and D. H o m e , have collected and
have g i v e n brief scientific explanations for
numerous examples of natural phenomena
and c o m m o n p l a c e activities. This book,
based on the a u t h o r s ' regular c o l u m n s in
Indian popular science magazines and
n e w s p a p e r s , is intended for the y o u n g w i t h
a high school background in science.
The book is divided into seven chapters of
questions and puzzles w i t h solutions,
f o l l o w e d by a chapter of u n a n s w e r e d
problems. The g r o u p i n g of questions is not
based on a t r a d i t i o n a l
curricular
classification of t o p i c s in p h y s i c s , but is
rather based on the locations w h e r e a puzzle
can be faced, such as in the kitchen, on the
playground, or in popular f i l m s and novels.
Q u e s t i o n s are posed on c o m m o n
occurrences and activities s u c h as the
buzzing of bees, the spin on tennis balls, and
the causes of lightning, as w e l l as on certain
aspects of science f i c t i o n , s u c h as the
theoretical f l a w in W e l l s ' Invisible Man. A s
w e l l , the t h o r o u g h solutions provided are
easy to c o m p r e h e n d and are not replete w i t h
the technical jargon abundant in puzzle
booksof a similarnature. However, themost
intriguing questions are f o u n d in the final
chapter of " u n s o l v e d " riddles, w h i c h involve
questions that remain u n a n s w e r e d , or have
c o m p l e x solutions. The m a j o r i t y of the
p u z z l e s are a c c o m p a n i e d by c o m i c a l
illustrations by Suparno Chaudhuri, w h i c h
enhance the laid-back s t y l e of the book and
reinforce its appeal t o lay persons. It is
u n f o r t u n a t e that the m a j o r i t y of solutions are
not enhanced w i t h figures and illustrations,
w h i c h greatly help in understanding the
underlying physical principles behind a
specific problem.
In all, Riddles in Your Teacup is a delightful
f o r a y into the deciphering of puzzles and
c o m m o n occurrences f o u n d in every day life,
lacking, h o w e v e r , the j a r g o n and technical
explanations that do not appeal t o the y o u n g
and t o lay persons. The price of $ 2 2 U. S., or
about $ 3 0 Canadian is t o o steep for a
p a p e r b a c k book of o n l y 1 7 3 p a g e s ;
nonetheless, the book is an ideal choice for
high school libraries, and may be added as an
interesting supplement to traditional high
school physics t e x t s . It is r e c o m m e n d e d ,
h o w e v e r , t o anyone w i t h an interest in
science, because, as Dr. Paul Davies aptly
states in the f o r e w o r d , "all scientists are
y o u n g at h e a r t " .
Samir C. Grover
1 4 0 5 B o r t o l o t t i Crescent
O t t a w a , Ontario
K1 B 5C1
Of One M i n d : The C o l l e c t i v i z a t i o n of
Science, par J . M . Z i m a n , AIP Press,
p p : x v i i + 4 0 6 , ISBN
1-56396-065-6;
QC 1 6 . Z 5 6 A 3 Prix: 2 9 , 9 5 $US (couverture
cartonnée).
J o h n Z i m a n n ' e s t plus qu'un e x - p h y s i c i e n
ayant t r o u v é refuge, après une carrière
scientifique f r u c t u e u s e , au d é p a r t e m e n t
d ' é t u d e s s o c i a l e s et é c o n o m i q u e s de
l'Impérial College à Londres. Du moins,
est-ce ainsi q u ' i l se présente, un peu à la
blague, dans le dernier d ' u n e trentaine
d'essais non-techniques rassemblés par les
Presses de l ' A m e r i c a n Institute of Physics
dans le c a d r e d e la série " M a s t e r s of M o d e m
P h y s i c s " . Rares sont ceux qui possèdent la
lucidité de longues années de pratique
conjuguée avec une c o m p r é h e n s i o n
t h é o r i q u e a p p r o f o n d i e d e l a s o c i o l o g i e propre
aux c o m m u n a u t é s scientifiques et des
m é c a n i s m e s g é r a n t l ' é v o l u t i o n de la
c o n n a i s s a n c e . T r o p s o u v e n t , les
c o m m e n t a i r e s et discours s ' i n s c r i v e n t dans
d e u x t r a d i t i o n s d é f i c i e n t e s : c e l l e s du
scientifique improvisé sociologue qui livre
une image m y o p e et navrante de son univers
familier ou du philosophe qui n'a de la
science q u ' u n e connaissance livresque bien
souvent dépassée ou t o u t bonnement
fausse. Ziman, h e u r e u s e m e n t , f a i t p a r t i e d e
l ' é l i t e des c o m m e n t a t e u r s de la v i e
scientifique et évite les écueils habituels.
127
Of One Mind:
The Collectivization
of
Science, le t o u t dernier recueil de J o h n
Z i m a n apporte donc une profondeur
rafraîchissante aux discussions entourant le
pourquoi et le c o m m e n t du processus de la
d é c o u v e r t e . L'auteur n ' h é s i t e pas un instant
à replacer dans une d y n a m i q u e sociale les
c o m p o r t e m e n t des chercheurs et l ' a v a n c é e
d e s c o n n a i s s a n c e s parla recherche. Ceci est
particulièrement vrai dans les portraits
critiques q u ' i l trace de quelques grands
physiciens tels Einstein, D y s o n et Landau, et
plus encore dans son analyse des
c h a n g e m e n t s f o n d a m e n t a u x qui ont
t r a n s f o r m é la recherche mais aussi la
c o m m u n a u t é de chercheurs depuis plus de
5 0 ans.
O n ne p e u t q u e r e g r e t t e r q u e l e s
bouleversementsdesdernièresannéesdans
la c o m m u n a u t é s c i e n t i f i q u e m o n d i a l e
échappent à l'analyse lucide de Z i m a n
puisque la plupart des essais rassemblés ici
f u r e n t écrits durant la première m o i t i é des
années 1 9 8 0 . A v e c la r é d u c t i o n marquée
des f o n d s pour les grands projets et la
f e r m e t u r e de g r a n d s l a b o r a t o i r e s de
recherche industrielle, il n'est pascertainque
la c o l l e c t i v i s a t i o n d e la science, qui justifie le
t i t r e du recueil, d e m e u r e la voie du f u t u r en
science. Sa d i s c u s s i o n des autres aspects
de la vie des scientifiques demeure valide,
t o u t e f o i s , que ce soit le côté néfaste du
j u g e m e n t par les pairs, les jeux de pouvoirs et
d e r e c o n n a i s s a n c e , le r e f u s par les
scientifiques
d'assumer
leurs
responsabilités, e t c .
Il n'est pas certain que t o u t physicien se
reconnaîtra dans le portrait de la science et
de la c o m m u n a u t é scientifique que trace
J o h n Ziman. Une chose est sûre, t o u t e f o i s ,
l ' i m a g e nuancée et c o m p l e x e d é c r i t e d a n s c e
livre ne peut que nous amener à réfléchir sur
nous m ê m e s , nos interactions avec nos
collègues et avec la société en générale, et à
découvrirqueplusieursdesmythesquenous
e n t r e t e n o n s sur notre c o m m u n a u t é ne
t r o u v e n t guère c o n t a c t avec la réalité.
Normand Mousseau
Département de physique
Université de M o n t r é a l
INVENTORS A N D DISCOVERERS, Changing
OurWorld.NationalGeographicSoc., 1 988,
pp 3 2 0 . ISBN 0 - 8 7 0 4 4 - 7 5 1 - 3 ;
0 - 8 7 0 4 4 - 7 5 2 - 1 d e l u x e a l k . paper; T 1 8 . I 5 7 .
Price: $ 2 1 . 9 5 he; 2 9 . 9 5 deluxe, he.
The i n t r o d u c t i o n t o t h i s eleven chapter opus
indicates that the scope of the book
presumes t o begin at the beginning of the
1 8 t h c e n t u r y a n d ends w i t h s o m e indications
of promises of the T e c h n o l o g y of T o m o r r o w .
The Power of Steam uses an historical
approach d a t i n g f r o m about 1 6 9 0 (Denis
Papin of France). A one page insert outlines
t h e w o r k of George and Robert Stephenson,
and a t w o - p a g e spread is dedicated to the
c o n t r i b u t i o n s of Robert Fulton, one of the
e a r l y s u c c e s s f u l d e v e l o p e r s of t h e
s t e a m b o a t . Chapter 3 takes us on an
historical t r i p into The Age of
Electricity
beginning w i t h the early w o r k of the V o l t a .
Special s u b - s e c t i o n s a r e d e v o t e d t o t h e w o r k
of T h o m a s Edison, NikolaTesIa, and Graham
Bell. On Wheels & Wingstakes on the s t o r y
of the m o t o r c a r s and airplanes. The f a m e d
G o t t l i e b Daimler and Carl Benz get a
three-page spread of their w o r k in car and
128
Physics in Canada
M arch/Aprill 9 9 6
motor development. Henry Ford's
c o n t r i b u t i o n t o the car industry is outlined in
a five-page section. The W r i g h t brothers
(Orville and Wilbur) also get a special
four-page s k e t c h of their c o n t r i b u t i o n to the
d e v e l o p m e n t of airplanes. The historical
d e v e l o p m e n t s of m o d e r n day materials is
f o u n d in Chapter 5, A World of
New
Materials. It begins w i t h the early w o r k s of
about 1 8 5 0 describing a t t e m p t s to make
" r u b b e r " into a " u s e f u l " product. Included is
an interesting look at the s t o r y of the n e w
plastics and alloys. Charles Goodyear
(rubber) and Leo Baekeland (Bakelite) have
special sub-sections d e v o t e d to their w o r k .
Capturing
the Image,
traces out the
d e v e l o p m e n t of p h o t o g r a p h y .
Special
inserts look at the life and c o n t r i b u t i o n s of
W i l l i a m Henry Fox Talbot, George Eastman,
and E d w i n Land. Strangely, t h o u g h , there is
no m e n t i o n of present-day digitization of
pictorial elements - w h i c h w o u l d bring the
reader t o the very latest a d v a n c e m e n t s in the
field of p h o t o g r a p h y . The chapter entitled
Messages by Wireless traces out the early
days of telegraphy, radio, radar, television. A
three-page biography of Guglielmo Marconi,
a n d a f o u r - p a g e d e s c r i p t i o n of t h e
c o n t r i b u t i o n s of Bell Laboratories scientists
- w h i c h include such notables as W a l t e r
Brattain, J o h n Bardeen, W i l l i a m Shockley,
and C l i n t o n Davisson - are indeed v e r y
interesting sub-sections of this chapter.
Power Particles deals mainly w i t h atomic
energy. A special section of t h e chapter is
d e v o t e d to the w o r k s of Ernest 0 . Lawrence
of c y c l o t r o n f a m e . A n o t h e r sub-section is
d e v o t e d to the c o n t r i b u t i o n s of Enrico Fermi,
the great nuclear physicist. M o d e r n day
inventions are based in large part on
c o m p u t e r chips, the subject of Chapter 9.
The history takes us f r o m the early days of
the abacus t o the m o d e r n age of c o m p u t e r s .
A special section of the chapter is d e v o t e d t o
John von Neumann, a name almost
s y n o n y m o u s w i t h c o m p u t e r design. The
penultimate chapter is entitled Engineering
Life. Here w e find reference t o the w o r k of
Jenner, Pasteur, Lister, and Paul Ehrlich. So
t o o are discussed the w o r k s of Fleming, of
Selman A. W a k s m a n , and of Banting and
Best, and Jean- François Borel. A special
section in this chapter is d e v o t e d t o the w o r k
of W i l l i a m J . K o f f , a pioneer in the field of
artificial organs. The t e x t proper ends w i t h
Technology of Tomorrow. It begins w i t h a
d i s c u s s i o n of t h e d e v e l o p m e n t of
s u p e r c o n d u c t o r s , t h e n goes on t o describe
some modern-day applications. There is also
a d e s c r i p t i o n of the potential of D N A studies
f r o m location of h u m a n genes t o the plans
for the analysis of the bases' sequencing.
The main body of the t e x t is f o l l o w e d by a
section about the authors, an important part
of the book, since INVENTORS A N D
DISCOVERERS, Changing Our W o r l d , is a
multi-author publication. A second s e c t i o n
on A c k n o w l e d g m e n t s , and a third on
Illustration Credits, precedes a six-page
t h r e e - c o l u m n per page Index. The special
inserts, w h i c h give u s a short biography of a
number of inventors and developers, are
easy t o spot as t o their beginning, but
s o m e t i m e s the end of the inserts are a little
harder t o locate. The t y p e s c r i p t is almost the
same as that of the main body, thus if y o u
are reading the main t e x t , it is s o m e t i m e s a
little bothersome t o have t o hunt t o find its
continuation!
The text is very w e l l edited. I f o u n d only one
slight error of vocabulary viz: on p. 4 5 , the
expression electric battery is used w h e n
electric cell is intended. Too, I w a s a m u s e d
by a line in discussing some of Graham Bell's
w o r k : " W h i l e vacationing at the Bell h o m e in
Ontario, Canada . . . " , (p. 54).
The illustrations are indeed excellent and the
w r i t e - u p s are v e r y w e l l done! It w o u l d be
excellent background material for use as
c o m p l e m e n t a r y material especially for
u n i v e r s i t y science lectures. On the other
hand, since the w o r k contains very little
m a t h e m a t i c s , anyone w i t h a m o d i c u m of
learning can profit f r o m its reading. I do
believe that it could be a source of
inspiration, for s t u d e n t s of all ages. Thus I
do b e l i e v e t h a t I N V E N T O R S A N D
DISCOVERERS, Changing Our W o r l d should
be f o u n d in all libraries.
Gérard Hébert, Emeritus
Dept of Phys. & A s t r o n .
York U n i v e r s i t y
LONG RANGE C A S I M I R FORCES, THEORY
A N D RECENT EXPERIMENTS O N A T O M I C
SYSTEMS, edited by Frank S. Levin, David
A.Micha,Plenum,Press, 1 993,ppxv + 357.
ISBN 0 - 3 0 6 - 4 4 3 8 5 - 6 ; Q C 6 8 0 . L 6 3 . Price:
$ 7 5 . 0 0 (he).
F o r t y - e i g h t y e a r s a g o , Casimir, m o t i v a t e d by
e x p e r i m e n t a l puzzles on t h e stability of
colloids s h o w e d that parallel uncharged
metal plates w e r e a t t r a c t e d by a f o r c e per
unit area equal t o w i t h i n a numerical
constant t o the reciprocal of the distance
b e t w e e n t h e m t o the f o r t h p o w e r t i m e s
Planck's c o n s t a n t and the speed of light. For
other s y m m e t r i c shapes the f o r c e can be
repulsive. It is not obvious intuitively w h y
the e f f e c t is proportional t o the speed of light
and h o w t o predict the sign of the e f f e c t .
Experimentally t h i s e f f e c t , and analogous
e f f e c t s all due to retarded interactions, have
been checked e x p e r i m e n t a l l y t o the order of
t e n percent.
It is the purpose of this book t o elucidate
recent a t t e m p t s t o measure Casimir forces
t o high a c c u r a c y in an a t o m i c physics
experiment. This first chapter by Spruch is a
d e l i g h t f u l t u t o r i a l , clear, discursive, amusing
on the physical origin of the Casimir e f f e c t s
and m u c h more. The m o s t sensitive m e t h o d
to study the Casimir f o r c e s appears t o be in
very high precision e x p e r i m e n t s on Rydberg
States of Helium.
Lundeendescribes beautiful e x p e r i m e n t s on
the n = 10 fine s t r u c t u r e of Helium. The
measurements, accurate t o better t h a n a
kilohertz, measure the small Casimir energy
c o n t r i b u t i o n s t o a p r e c i s i o n o f 10 percent. In
order t o determine the Casimir energies it is
n e c e s s a r y t o k n o w all o t h e r e n e r g y
c o n t r i b u t i o n s i n c l u d i n g r e l a t i v i s t i c and
q u a n t u m e l e c t r o m a g n e t i c t o a very high
accuracy.
Drake, w h o calculates the
non-relativistic energies t o better t h a n
f o u r t e e n figures and also the relativistic and
Lamb shift c o n t r i b u t i o n s , presents clearly
the p r o c e d u r e s a n d r e s u l t s o f this remarkable
numerical w o r k . D r a c h m a n , in the spirit of
Rydberg, calculates the energies of these
states in perturbation t h e o r y . A l t h o u g h not
as accurate as the numerical calculation, his
results are perhaps easier t o interpret
physically and are s u f f i c i e n t l y accurate for
t h e e x i s t i n g e x p e r i m e n t . Finally Sucher and
Feinberg present a m o r e " h i g h b r o w "
account of the t h e o r e t i c a l f o u n d a t i o n s .
M u c h of this book is a joy t o read - so put
d o w n y o u r C h r i s t i e m y s t e r y and pick up your
"Casimir Forces".
Dr. F . W . Dalby
UBC
Q U A N T U M
M E C H A N I C S ,
AN
I N T R O D U C T I O N FOR DEVICE PHYSICISTS
AND
ELECTRICAL
ENGINEERS,
by
D . K . Ferry, IOP, 1 9 9 5 , pp: ix + 2 8 8 . ISBN
0 - 7 5 0 3 - 0 3 2 7 - 1 <hc) 0 - 7 5 0 3 - 0 3 2 8 - X (pbk).
This book uses a nont ri vial a p p r o a c h to t e a c h
quantum mechanics,
by e m p h a s i s i n g
m o d e r n applied a s p e c t s . The m a t e r i a l is v e r y
c o n c i s e and t o the p o i n t . N o t e t h a t t h i s could
cause s o m e p r o b l e m s t o f r e s h m e n . H o w e ver
if w e ever w a n t t o e x c i t e s t u d e n t s about
q u a n t u m m e c h a n i c s , w e should s h o w t h e m
h o w useful it really is: this book does that in
an excellent w a y .
Q u a n t u m M e c h a n i c s ... is d i v i d e d into 9
chapters. Following theintroductorychapter
w h i c h i n t r o d u c e s the c o n c e p t of w a v e s and
particles and discusses
modern
n a n o s t r u c t u r e e x p e r i m e n t s , the next s e v e n
chapters guide the reader t h r o u g h
S c h r o e d i n g e r e q u a t i o n , tunnelling, h a r m o n i c
oscillator.operators.perturbationtheoryand
m o t i o n in c e n t r a l l y s y m m e t r i c p o t e n t i a l s .
The last and m o r e a d v a n c e d chapter deals
w i t h e l e c t r o n s and a n t i - s y m m e t r y .
Q u a n t u m M e c h a n i c s ... c a n be used as a
t e x t b o o k for t e a c h i n g Q M since every
c h a p t e r is s u p p l e m e n t e d w i t h several
p r o b l e m s . I s t r o n g l y r e c o m m e n d this as
supplementary
reading
to
students
s t u d y i n g Q M , but not as a first t e x t b o o k .
S t u d e n t s s t u d y i n g it w i l l f i n d a v e r y useful
m a t e r i a l that illustrates i m p o r t a n t a s p e c t s
of m o d e r n s o l i d - s t a t e e l e c t r o n i c s and
q u a n t u m m e c h a n i c s . These t o p i c s are
b e c o m i n g m o r e and m o r e i m p o r t a n t in
t o d a y ' s m i c r o e l e c t r o n i c and o p t o e l e c t r o n i c
d e v i c e s , not t o m e n t i o n the n e w e m e r g i n g
field of n a n o e l e c t r o n i c s .
In conclusion, this book will be a valuable
addition not only as a teaching source for
quantum mechanics but also as a source of
information on the principles of modern
nanoelectronic devices for research physicists.
Dr. M a r e k W a r t a k
D e p a r t m e n t of Physics and C o m p u t i n g
W i l f r i d Laurier U n i v e r s i t y
PALE BLUE D O T : A V I S I O N OF THE
H U M A N FUTURE IN SPACE, by Carl
Sagan, R a n d o m H o u s e , N e w Y o r k , 1 9 9 4 ,
pp
xviii + 4 2 9
ISBN
0-679-43841-6
(hardcover)
Carl Sagan is a w e l l - k n o w n planetary
a s t r o n o m e r and science popularizer, t h e
latter m o s t n o t a b l y for his " C o s m o s "
t e l e v i s i o n series. In t h i s book he d i s c u s s e s
a w i d e range of t o p i c s related to the
general t h e m e of p l a n e t a r y a s t r o n o m y and
the e x p l o r a t i o n of the solar s y s t e m , at a
level similar to " C o s m o s " , i.e. suitable for
the " i n t e r e s t e d lay r e a d e r " . Like his other
w o r k s , t h i s book blends s c i e n c e , h i s t o r y ,
s p e c u l a t i o n s o n the f u t u r e , and the
a u t h o r ' s o w n philosophical and
views.
political
The author begins by e x a m i n i n g " . . . the
w i d e s p r e a d c l a i m s m a d e o v e r all of h u m a n
h i s t o r y t h a t our w o r l d and our species are
unique, and even central to the w o r k i n g s
and purpose of the C o s m o s . "
He
describes h o w these claims have gradually
yielded t o m o d e r n s c i e n t i f i c v i e w s of our
u n p r i v i l e g e d place in a naturalistic c o s m o s
and our essential s i m i l a r i t y to other
species. Readers of d i f f e r i n g philosophical
or religious persuasions might take issue
w i t h the a u t h o r ' s s t r o n g l y a r t i c u l a t e d
h u m a n i s t i c v i e w s here, but I f o u n d these
i n t e r e s t i n g and q u i t e c o m p e l l i n g , t h o u g h
somewhat
disconnected
from
the
remainder of the b o o k .
T h e author t h e n m o v e s o n t o t h e c e n t r a l
f o c u s of the b o o k : the u n m a n n e d r o b o t i c
e x p l o r a t i o n of the planets. He first briefly
d i s c u s s e s the e x t e n t to w h i c h life on Earth
is d e t e c t a b l e f r o m space at v a r i o u s
resolutions and w a v e l e n g t h s .
He t h e n
describes in more detail various m i s s i o n s
by the U n i t e d States and the f o r m e r Soviet
U n i o n to the V e n u s , M a r s , J u p i t e r , Saturn,
Uranus, and N e p t u n e s y s t e m s . The author
does an excellent j o b of c o n v e y i n g the
e x c i t e m e n t of s c i e n t i f i c d i s c o v e r y here,
d e s c r i b i n g several cases of c o n f l i c t i n g
results and i n t e r p r e t a t i o n s of a m b i g u o u s
data. I particularly enjoyed his d i s c u s s i o n
of the c o n f l i c t i n g evidence for w h e t h e r
Saturn's
moon
Titan
may
have
h y d r o c a r b o n lakes or oceans.
The
author
argues
strongly
that
a s t r o n o m y , by its v e r y nature, tends t o
foster
international
cooperation:
researchers " . . . d i s c o v e r that splendid
w o r k , w o r k that c o m p l e m e n t s their o w n , is
being done by researchers in other nations;
or that t o solve a p r o b l e m , y o u need data
or a p e r s p e c t i v e (access to the s o u t h e r n
s k y , for example) that is unavailable in
your c o u n t r y . " .
He describes several
e x a m p l e s of i m p o r t a n t global e f f e c t s on
Earth that w e r e first d i s c o v e r e d
by
planetary a s t r o n o m e r s , n o t a b l y the danger
of nuclear
winter
and the d e p l e t i o n of
the ozone layer by
® C.A.P. 1 9 9 6 .
chlorofluorocarbons.
Like
most
astronomers,
the
author
is
very
s k e p t i c a l of m a n n e d
space p r o g r a m s . He
d i s c u s s e s the A p o l l o
program's
minimal
e m p h a s i s
on
science,
and
ponders
at
some
length
whether
future
manned
missions to
Mars
are
a
justifiable
e x p e n d i t u r e in the
late 2 0 t h and early
2 1 s t c e n t u r i e s . The
author t h e n turns t o
a c o n s i d e r a t i o n of
the
consequences
and
likelihood
of
catastrophic comet
or asteroid i m p a c t s
on t h e earth. He argues t h a t i n v e n t o r y i n g
p o t e n t i a l l y - i m p a c t i n g bodies is " . . . p r u d e n t ,
i t ' s g o o d s c i e n c e , and it d o e s n ' t c o s t
m u c h . " . But he argues s t r o n g l y against
the i m m e d i a t e d e v e l o p m e n t of s y s t e m s t o
d e f l e c t s u c h bodies, because of their
immense
potential
for
misuse,
by
d e f l e c t i n g o t h e r w i s e near-missing bodies to
hit the Earth. He argues that i t ' s better t o
w a i t - and take the roughly 1 in 1 0 0 0 risk
of a c a t a s t r o p h i c i m p a c t - until h u m a n i t y is
(hopefully) more unified in a c e n t u r y or
t w o . The author f o r e c a s t s that h u m a n i t y
m a y have a w e l l - d e v e l o p e d , unified, and
environmentally
benign
Earth-wide
c i v i l i z a t i o n by the 2 2 n d c e n t u r y . A s s u m i n g
this, he argues that w e , and indeed all
civilizations at c o m p a r a b l e stages of
d e v e l o p m e n t , w i l l i n e v i t a b l y bo d r i v e n to
v o y a g e out into our solar s y s t e m .
He
d i s c u s s e s the p r o s p e c t s for t e r r a f o r m i n g
V e n u s , M a r s , and a f e w of the J o v i a n and
Saturnian m o o n s .
Finally, the author d i s c u s s e s SETI: the
search for e x t r a t e r r e s t r i a l intelligence. In
the past 35 years this has g r a d u a l l y
b e c o m e a serious b r a n c h of a s t r o n o m y ,
and a g r o w i n g n u m b e r of increasingly
s e n s i t i v e searches have been m a d e . The
author describes s o m e of major radio SETI
searches t o d a t e , and the p r o s p e c t s for
much
more
sensitive
and
hopefully
b e t t e r - f u n d e d ones in the f u t u r e .
He
outlines s o m e of the a r g u m e n t s regarding
the Fermi paradox (if t h e y ' r e out there,
w h y h a v e n ' t w e seen t h e m y e t ? ) , and
closes w i t h s o m e s p e c u l a t i o n s on a d i s t a n t
f u t u r e w h e n h u m a n s v o y a g e t o the s t a r s .
Overall, I enjoyed t h i s b o o k . I f o u n d t h e
author's
wide-ranging
discussions
fascinating,
inspiring,
and
thought-provoking.
The m a n y
color
photographs
and
paintings
nicely
c o m p l e m e n t the t e x t , and are beautifully
reproduced.
The book d e s e r v e s a w i d e
readership.
Jonathan Thornburg
thornbur@theory.physics.ubc.ca
Physics D e p a r t m e n t , UBC
All rights reserved.
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The above permission does not extend to other kinds
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new collective w o r k s , or for resale.
For such
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129
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Information regarding the department can be seen on our web
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The Corporate Members of the Canadian Association of
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educational activities of the Association.
Les membres corporatifs de l'Association canadienne
physiciens et physiciennes sont un groupe
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Fund and are tax deductible.
Les revenus de leurs contributions déductibles aux fins
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Physics in Canada La Physique au Canada

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