10mw klystron
DESCRIPTION
SuperKEKB injector upgrade for high charge and low emittance electron beam. M. Yoshida, N. Iida, Y. Ogawa, T. Osawa , Z. Lei T. Natsui , M. Sato, H. Sugimoto, X. Zhou High Energy Accelerator Organization (KEK). Ir 5 Ce Photocathode. High charge & low emittance RF-Gun :. - PowerPoint PPT PresentationTRANSCRIPT
窓
10MWKlystron
1.5m RF-Deflector
SuperKEKB injector upgrade for high charge and low emittance electron beam.
M. Yoshida, N. Iida, Y. Ogawa, T. Osawa, Z. Lei T. Natsui, M. Sato, H. Sugimoto, X. ZhouHigh Energy Accelerator Organization (KEK)
Present projected emittance measurement
Emittance measurement at 5-sectorAB
1C 2 3 4 5
PF InjectorWeak lens
0
100
200
300
400
500
600
0 20 40 60 80 100 120C to sector Q-magnet[ % ]2
Emittance (m
m m
rad)
Project emittance using weak lens
screen
sin2
/
10 , 2.856 , 10 ,
deflector RFscreen deflector screen deflector screen
beam
x screen screen
deflector deflector RFx
screen beam
deflector RF deflect
eV tx
E
eV tx
E
V MV f GHz t ps
screen
screen
10
/ 3
22 , 11.424 , 10 , 10
/ 27
or
x
deflector RF deflector
x
m
x
V MV f GHz t ps m
x
zRF-Deflector
x
y
( ) ( )y y yt t
t
Transverse Wakefield Measurement => Initial offsetusing X-band RF-Deflector
Beam diagnostic station In third switch yard
Input Power : 10MWDeflecting Voltage : 22 MV
RF-Deflectordeveloped by SLAC
for LER4.0 GeV 4nC x 2y < 6 mm mradfor HER
7.0 GeV 5nC x 2y < 20 mm mrad
Longer bunch can reduce space charge effect inside RF-Gun and also CSR at J-ARC.
Due to mis-alignment:- Dispersion - Short range wakefield
AB
C 1 2 3 4 5Target @1-43.5 GeV 10nC x 2
1.1GeV@DR
ECS
RF-Gun5-10nC
C-band
ECSBCS
PFJ-ARC
Beam diagnostic station
KEKB obtained(e+ / e-)
SuperKEKB required (e+ / e-)
Beam energy 3.5 GeV / 8.0 GeV 4.0 GeV / 7.0 GeV
Bunch charge e- e+ / e-10 1.0 nC / 1.0 nC
e- e+ / e-10 4.0 nC / 5.0 nC
Beam emittance (g)[1] 2100 mm / 300 mm 6 mm / 20 mm
High charge low emittance is required for SuperKEKB.
RF-Gun
40 nC
RF-Gun
- High charge & low emittance RF-Gun- Cavity with electric focusing field- Disk and Washer => 3-2- Quasi Traveling Wave => A-1
- Long life cathode QE : 10-4
- LaB6, Ir5Ce at room temperature- High power laser > mJ @ 266nm- Nd doped solid state laser- Yb doped fiber & solid state laser
- Beam transport- Alignment- Emittance preservation- Beam diagnostics
3-2A-1
C-1
Linac beam line
Injection beam line on the angle
3-2 RF-Gun (from Sep 2011) :- PF/PF-AR Injection during SuperKEKB construction phase - 5nC test stand for SuperKEKB
High charge & low emittance RF-Gun :A-1 RF-Gun (will install until Sep 2012) - Cavity : Higher electric focusing field
=> Quasi traveling wave
- Cathode -Ir5Ce at room temperature => QE :10-4
- LaB6 or Ir5Ce with heater => QE :10-3
- Laser : Higher power & stable laser=> Yb based chirped pulse amplification
Present beam statue
Cavity : Disk and Washer
Laser : Nd doped solid state laser
- Nd:YAG 5-stage amplifier
- Nd:YVO4 + SESAM passive modelock oscillatorDAW-type RF gun (90 MV/m, 5 mm-mrad, 3.2 MeV)
BNL-type RF gun (120 MV/m, 11.0 mm-mrad, 5.5 MeV)
Quasi traveling wave side couple RF gun
(100 MV/m, 6mm-mrad, 13.5 MeV)
BNL (3.8 mm)
QTW (0.2 mm)
DAW (1.7 mm) Beam Size
Cathode : LaB6 => Ir5Ce
Cathode rod
Ir5Ce Photocathode
Simulation of projected emittance
σz=0.75mmσa=0.3mm
σz=2 mmσa=0.3mm
σz=0.75mmσa=0.1mm
σz=2 mmσa=0.1mm
1st order
2nd order
Projected emittance dilution due to transverse wakefield
Beam tracking simulation :Intial emittance : 6 mm mradMis-alignment : = 0.3mm Initial offset
Initial offset scan to compensate transverse wakefield
Wire scanner should install more.AB
1C 2 3 4 5
J-ARC PF Injection
0
100
200
300
400
500
600
700
800
B C 5Sector
gy [
mm
mra
d]
0.5nC1nC3nC5nC1.0nC 3.0nC 5.0nC 7.0nC
0
200
400
600
800
1000
1200
1400
B C 5Sector
gx [
mm
mra
d]
0.5nC1nC3nC5nC1.0nC 3.0nC 5.0nC 7.0nC
Existing wire scanner
DC-Gun
Consideration of bunch compression using J-ARC
Beam tracking simulation
Pulse Q-magnet & pulse steering
Emittance preservation :