Proposal for Japan-US collaboration on New Test Facility for Novel Accelerator R&D (FACET at KEK)
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Transcript of Proposal for Japan-US collaboration on New Test Facility for Novel Accelerator R&D (FACET at KEK)
Proposal for Japan-US collaboration onNew Test Facility for Novel Accelerator R&D
(FACET at KEK)
M. Yoshida, K. Nakajima,M. Sato, S. Matsumoto,
M. Nozaki, S. YamaguchiNovel Accelerator Promotion Office in KEK
Japan-US collaboration for me• Development of klystrons
and other electron tubes.(Mitsubishi / Toshiba)Technologies are based on Japan-US collaboration.
• Concerning to beam driven accelerator region,U.S. has many experiences for more than 10 years.We have to learn more about this region.
=> ILC after burner etc.
New concept IOT for ERL
DRFS klystron / L-band 40 MW etc.
FACET at SLAC
1.19 GeVσz= 5.5mm=18 psεx,y=50 x 5 mm ・ mrad
23 GeV, 3nCσz=14μm=50 fsσx,y = 10 μmβ ~ 1 m
0.4 ps
At FFTB experiment : Gradient : PWFA(>30GV/m), DWA(>16GV/m).Total acceleration voltage : > a few GeV.
We are discussing with Dr. Mark Hogan.
FACET at KEK
BCS
Install Photocathode RF-Gun
z=1 ps, q > 5nC, εx,y < 20 mm ・ mrad
Total length ~400m => 9 GeV
8 GeV LINAC from 1998
e+ Damping Ring(under construction)
e- 9 GeV, 5nCσx,y = 35μ m (β ~ 1m)
e+ 4 GeV, 5nCfrom damping ring
ExperimentalArea
ps modulatedlaser 40 TW laser
Target for FACET in KEK• Continuous novel accelerator facility until Super-
KEKB shutdown ~ 2025 ?• Short pulse laser complex facility :
Laser modulated photo cathode RF-Gun and LWFA injector for femtosecond witness beam.
• User facility for University etc.~ 100 fs electron bunch
LWFA fs witness bunch
DWA (or PWFA)
Ex. DWA2
,4 2 / ( 0.1 )8
1
b e ez dec t
z
N r m ceE GV m psa a
×Transformer Ratio(~ 3)
Single-wall DWA:
Multi-wall or photonic DWA with multi femtosecond bunch:
For microwave:Klystron : 350 kVAccelerator : 35 MV/m => transformer ratio = 100
+
Laser modulatedmicro bunch structure
Higher Transformer ratio
DWA experiment is just started using another low energy fs beam.
8 GeV LINAC Third Switch YardKEKB(continuous inj.)
PF (top up)
AR(2 inj./day)
8 GeV LINAC Gun
Third Switch Yard
Damping ring(under construction)
Experimental Area (beam damp)
Beam diagnostic station &FACET at KEK LINAC Beam damp
Pulse bend for PF
~ 2014 : no injection to KEKB↓
2014 ~ : beam switch for KEKB/PF & Beam Damp
Key technologies• Laser plasma injector
– The witness beam.– Sub-fs beam.
• Fast beam switch (completed)– Event system– Pulse bend
• RF-Gun (will be installed soon)– Velocity bunching DAW => high charge & low emittance– Modulated laser => micro bunch structure.
• X-band for harmonic compensation and bunch compression.– Also use for Beam Diagnostic Station for LINAC Upgrade : B
unch Length / Sliced Emittance
Laser Plasma Injector
• Stacked capillary
• 40 TW laser is enough for self-injection– Upgrade existing TW laser
Discharged byYAG laser
LWFA injector for femtosecond witness beam
Fast beam switch• 50 Hz Event System (completed)
• Pulse Bend (installed)
Damp
FACET
Beam Damp Mode
KEKB e-KEKB e+
ExperimentalArea
New beam line is required
Velocity bunching DAW RF-Gun
1/4 Transient Angle1z ps
Linear velocity bunching will be expected to generate higher charge bunch > 10nC
+ Laser modulation
Micro bunchstructure
X-band• Harmonic compensation (suppress second
term)
• Bunch compression
42
2
1cos 2 cos 2 1
,
S X SS X X
SXX X
S X
z zE z V V az VN
VN VN
3sin 2
/ 56
BC BCX
BC
zE z V bz cz V
z z E E R
Nextef : =>- 3 PPM klystrons.- 150 MW
Summary• FACET at KEK is considered to
construct the beam driven and short laser complex facility, it has some different aspects compared with FACET at SLAC.
• KEK 8 GeV LINAC has unique ability for novel accelerator test facility except for SLAC in the world.
• It is expected to become a good complementary project to FACET at SLAC.