1. Crab Cavity R&D Plan
Kirk 1
6/Dec/2016

2. Outline Description in RDR/TDR Brief History
Comparison of Specification
R&D plan in F.Y
Summary
6/Dec/2016

3. Reference Design Report
Crab cavity in collider works for increasing luminosity!
The original design is based on 13-cell 3.9GHz deflecting cavity for Kaon separator.
6/Dec/2016

4. Technical Design Report
Description for Crab Cavity in only 1 page!
The most important thing is “in-phase operation” between electron and positron cavities.
We need more detailed specification table for ILC Crab cavity.
6/Dec/2016

5. Brief History
R&D for Crab cavity has been originally done by U.K. and U.S. collaboration
In 2009, this R&D was completely stopped due to budget issue
“In-phase operation” was done in vertical cryostat, not cryomodule
NRI judged ILC Crab Cavity as “Not matured technology”
We need to restart this R&D from F.Y. 2016
6/Dec/2016

6. Comparison of Specification
Crab
3rd
Crab
Developer laboratory
Lancaster Univ./FNAL/SLAC
INFN/LASA
KEK RF
3.9GHz
MHz
# of cell 9 1
# of cavity / module
2 cavities
8 cavities
1 cavity
# of modules
2 modules
1 module
RF operation mode
Pulse, 5Hz, 1.65msec
Pulse, 10Hz, 1.1msec CW
Operational temp.
1.8K
2.0K
4.2K
Cavity performance spec.
Ekick=5MV/m, Q0=109
Eacc=15MV/m, Q0=109
Esp=21MV/m (1.44MV), Q0=109
Drive power
~3kW
~6.3kW
~100kW QL
~106
4.3 x 106
1.6 x 105
QL tuning ?
3 stub tuner in waveguide
fixed
Frequency Tuner
Blade
Motor / Coaxial beampipe
Piezo Tuner
? (Not necessary for low gradient)
Not used
1 Piezo (well broken)
Helium tank
Titanium / TIG Welding
SUS316L / TIG Welding
Magnetic shielding
? (Inside is better)
Outside of Helium tank
Inside of Helium tank
LOM damping
Hook type antenna
Coaxial beampipe
SOM damping
Hook type antenna for vertical coupling
Squashed cell / Coaxial beampipe
HOM damping
1 HOM coupler (Not enough)
2 HOM couplers
2 HOM absorbers
Notch filter for crab mode
Symmetric position
Notch filter in coaxial beampipe
6/Dec/2016

7. ILC Crab Cavity is quite different from KEKB Crab Cavity!
Crab Cavity in KEKB
ILC Crab Cavity is quite different from KEKB Crab Cavity!
6/Dec/2016

8. Consideration of Cavity Package
Basically, mechanical design is based on 3rd harmonic cavity package for E-XFEL
Input coupler/Waveguide
Tuner/Helium tank/2-phase pipe
HOM coupler
HOM antenna
Cavity Fabrication Facility (CFF) team in KEK can help us!
And, we hope the international collaboration about it.
6/Dec/2016

9. R&D Plan in F.Y
Single cavity package w/ cavity, coupler, tuner will be (or maybe) tested in AR-E Lab in 2019.
Prototype CM in DESY
Horizontal Test Lab. in KEK
6/Dec/2016

10. Summary Crab cavity R&D for ILC will restart from F.Y. 2016 in KEK
Detailed specification table, based on TDR, is necessary
3rd harmonic cavity for E-XFEL looks useful for ILC Crab cavity
Prototype cavity package will be fabricated and tested in KEK
6/Dec/2016

11. Thank you very much for your attention
6/Dec/2016