Acceleratori Futuri -‐ 1

Acceleratori Futuri -­‐ 1 Massimo.Ferrario@LNF.INFN.IT XXVIII Seminario Nazionale di Fisica Nucleare e Subnucleare – Otranto 4 Giugno 2016 Fermi Globatron: ~5000 TeV Proton accelerator
1954 è 1994
Bmax 2 Tesla
ρ 8000 km
fixed target
3 TeV cm
170 G$
Globatron energy was comparable to the highest energy cosmic ray proton
known at the time.
ADA: (Anello Di Accumulazione), 1961-1964
the first e+e- Collider
ECM ≈ 2 E1m2
ECM ≈ 2 E
Fixed Target equivalent accelerator energy versus year
GeV
Hawking: the Solartron
Without further novel technology, we will eventually need an
accelerator as large as Hawking expected.
The Universe in a Nutshell, by Stephen William Hawking, Bantam, 2001
Accelerator on a Chip?
Future of Accelerators FCC
LHC HiLumi
E-XFEL
SuperKEKb
FAIR ILC
Conceptual
Design started
muons
Technical Design exists
Waiting funding decision
LHeC ERL
SwissFEL
ESS
LBNL LWFA 2014
Hadron acc. project
Lepton acc. project
Hadron acc. proposal
Lepton acc. proposal
R. Assmann, EAAC 2015, 9/2015 Modern accelerators require high quality beams:
==> High Luminosity & High Brightness
==> High Energy & Low Energy Spread
– N of particles per pulse => 109
– High rep. rate fr=> bunch trains
N e + N e− f r
L=
4 πσ xσ y
– Small spot size => low emittance
2I
Bn ≈ 2
εn
– Short pulse (ps to fs)
– Little spread in transverse
momentum and angle => low emittance
2 WAYS NTA ROAD MAP
①  Miniaturization of the accelerating
structures (resonant)
②  Wake Field Acceleration (transient)
(LWFA,PWFA,DWFA)
• 
• 
• 
Power sources
Accelerating structures
High quality beams
$ E = γE'
x
& x
%
β ' β
B
=
γ
Ex = Ex
& y
'
c
c
€
# ωt &
eE x
F⊥ ≅ 2 cos % 2 (
2γ
$ 2γ '
€
Taking into account the boundary conditions the accelerating
component of the field becomes:
Ez ( x,z,t ) = ( E+ sin θ )e
iωt−ik( z cosθ −x sin θ )
− ( E+ sin θ )e
iωt−ik( z cosθ +x sin θ )
= 2iE+ sin θ sin( kx sin θ )e iωt−ikz cosθ
x-SW
pattern
z-TW
pattern
xy
E-
2d
Ez
E+
d
d/2
E+
Ez
E-
β≈1
z
vφz =
€
ω
ω
c
=
=
>c
k z k cos θ cos θ
vϕ ≡ c
Conventional RF accelerating structures
High field ->Short wavelength->ultra-short bunches-> low charge
High field ->Short wavelength->ultra-short bunches-> low charge
Miniaturization of the accelerating
structures
Measured so far:
@ 130 GHz
⇒ 300 MV/m acceler.
(INFN-NORCIA)
Accelerator on a Chip
Dielectric Structure Design
Philosophies
—  Why dielectric?
—  Dissipation and breakdown in metals
—  Why photonic structures?
—  Natural in dielectric
—  Advantages of burgeoning field
—  design possibilities
—  Fabrication
Laser pulses
180 degrees
out of phase
e-beam
Biharmonic ~2D structure
—  Dynamics concerns
—  External coupling schemes
Schematic of GALAXIE
monolithic photonic DLA
Laser-Structure Coupling: TW
GALAXIE Dual laser drive structure, large reservoir of power recycles
Laser pulses
(180 degrees
out of phase)
e-beam
5th Gen Light Source: A Table-top X-ray FEL
P [W]
GALAXIE: GV-per-meter AcceLerator And
Ultra-high brightness
X-ray-source Integrated Experiment
6
electron source
10
<2 m 800 MeV Dielectric
5
LCLS
photons
in <1m(DLA)
10
Laser
Accelerator
<2 m EM
undulator
4
10 um)
(λ=100
3
10
2
10
40 keV quantum
SASE
FEL
1
10
0.0
0.2
0.4
0.6
z [m]
0.8 Long wavelength
(5 um) laser source
All EM system with GV/m fields
Many interconnected physics challenges
Ambitious program supported by DARPA AXiS initiative
Plasma Wake Field Acceleration 0
Plasma Oscillations
Surface charge density
Surface electric field
Restoring force
Plasma frequency
Plasma oscillations
Breakdown limit?
What about positrons?
positrons
300 µm
Wake Field Acceleration 1
Laser Driven
LWFA
Direct production of e-beam
Laser beam
1 mm
Electron beam
Active Plasma Lens
! µo I c $
Fr = ec #
r = ecBϑ' r
2&
" 2π Rc %
Protons and Ions?
TNSA
Wake Field Acceleration 2
Beam Driven
PWFA
Blumenfeld, I. et al. Energy doubling of 42 GeV electrons in a metre-­‐scale plasma wakefield accelerator. Nature 445, 741–744 (2007). Litos, M. et al. High-­‐efficiency accelera@on of an electron beam in a plasma wakefield accelerator. Nature 515, 92–95 (2014). 2014 Results: Two-Bunch Acceleration in a 1.5 m Plasma
Plasma Density:
3 ⇥ 1016 [cm
3
]
5 ⇥ 1016 [cm
3
]
8 ⇥ 1016 [cm
3
]
We are working to
improve our
spectrometer’s
ability to precisely
quantify energy
spread.
Results from last week! Good agreement between observed and
expected energy gain in a longer plasma for several plasma densities.
70
Positrons and Hollow Channel Plasma
•  A special optic called a kinoform is
used to create a hollow channel
plasma.
−400
−400
−300
−300
−200
−200
−100
−100
Y [µm]
•  Hollow channel plasmas might be
a viable method for accelerating
positrons in a plasma.
Laser Profile forJ5 @
J560Bessel
Focus
cm
Y [µm]
•  The physics of accelerating
positrons in a plasma is different
than that of electrons!
0
0
100
100
200
200
200 µm
300
400
−400
−200
0
X [µm]
300
200
400
−400
400
J4 @ 60 cm
−400
−400
Positrons plasma acceleration is a crucial step
−300 towards a plasma based
linear collider. FACET hosts the only active−200
research on positron PWFA.
0
−200
71
−100
Y [µm]
Y [µm]
−100
−300
0
ILC – International Linear Collider
Dielectric Wakefield Accelerator
§  Electron bunch (β ≈ 1) drives wake in
*
cylindrical dielectric structure
§ Dependent on structure properties
§  Generally multi-mode excitation
§  Wakefields accelerate trailing bunch
§  Mode wavelengths (quasi-optical
§  Design Parameters
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it again.
The
image
canno
t be
T
h
e
i
m
§  Peak decelerating field
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your computer, and then open the file again. If the red x still appears, you
may have to delete the image and then insert it again.
Extremely good
beam needed
§ Transformer ratio (unshaped beam)
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computer may not have enough memory to
open the image, or the image may have been
corrupted. Restart your computer, and then
open the file again. If the red x still appears,
you may have to delete the image and then
insert it again.
Ez on-axis, OOPIC
3 Steps towards a reliable PWA
①  High Gradient – Low e- Beam Quality
②  High e+e- Beam Quality – Low Gradient
③  High e+e- Beam Quality - High Gradient Horizon 2020: First Decisions on EU Design Studies in 2015 •  Two design studies approved in the accelerator area. Big success for
accelerator field!
Amazing success for
novel accelerators!
R. Assmann, EAAC 2015, 9/2015 R. Assmann, EAAC 2015, 9/2015 Moving towards a European Plasma Acc. in the 2020’s Invited to prepare contract at end of July 2015 à Excellent
signal from European Commission – Research and Innovation
R. Assmann, EAAC 2015, 9/2015 EuPRAXIA Research Infrastructure
Goal Parameters
R. Assmann, EAAC 2015, 9/2015
EuroCirCol Arc Design
EU co-­‐funded design study for FCC-­‐hh, focus on core acZviZes Accepted in 2015 EIR Design
Japan KEK Cryo Beam Vacuum
Finland TUT United Kingdom STFC, UNILIV, UOXF Netherlands UT Germany KIT, TUD France CEA, CNRS CERN Switzerland EPFL, UNIGE Italy INFN Spain ALBA, CIEMAT M. Boscolo, What Next 2016 High Field
Magnet
CERN TUT CEA CNRS KIT TUD INFN UT ALBA CIEMAT STFC UNILIV UOXF KEK EPFL UNIGE NHFML-­‐FSU BNL FNAL LBNL IEIO Finland France France Germany Germany Italy Netherlands Spain Spain United Kingdom United Kingdom United Kingdom Japan Switzerland Switzerland USA USA USA USA rd
3 EAAC 2017 September, 2017 Isola d’Elba TALKS DINNER LUNCH COFFEE DISCUSSIONS BREAKFAST Commenti Finali
• 
I grandi progetti spesso trascinano sviluppi tecnologici inaspettati e rivoluzionari
(FCC, EUPRAXIA, Muon collider?).
• 
Grande interesse internazionale nello sviluppo di nuove tecniche di accelarazione =>
alti gradienti, macchine compatte, => utilizzabili non solo per la fisica fondamentale
ma anche in ospedali, in campus universitari e per applicazioni industriali.
• 
La tecnologia dei laser di potenza avra’ sempre maggior importanza anche nel
mondo degli acceleratori.
• 
Lunga tradizione nell’INFN nello sviluppo tecnologico e creativo nel campo della
fisica degli acceleratori. Ben posizionata anche nei nuovi progetti internazionali.
• 
Ruolo fondamentale delle test facilities (BTF, SPARC_LAB)
• 
“L'INFN promuove, coordina ed effettua la ricerca scientifica nel campo della fisica
nucleare, subnucleare, astroparticellare e delle interazioni fondamentali, nonché la
ricerca e lo sviluppo tecnologico pertinenti all'attività in tali settori, prevedendo
forme di sinergia con altri enti di ricerca e il mondo dell'impresa”