1. Input coupler assembly, high power and thermal performance in S1-Global at KEK
E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing

2. Outline Introduction and QL of variable coupling
Conditioning at room temperature
High power performance and Inspection
Measurement of dynamic heat load
Summary
S1-Global cryomodule
installed in the STF tunnel
E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing

3. Input Couplers in S1-Global Cryomodule
AES004
ACC011
Z108
Z109
MHI-05
MHI-06
MHI-07
MHI-09
FNAL cavity
DESY cavity
KEK cavity
Four STF-2 Coupler (KEK)
Four TTF-III Couplers (DESY/FNAL)
E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing

4. QL of Variable Input Coupler
QL = 2.4 x 106
D f bw = 542 Hz
Cryomodule – A
(STF-2 couplers)
Cryomodule – C
(TTF-III couplers)
2.4 X 106
E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing

5. High Power System in S1-Global
Cryomodule-A
4 KEK cavities
(MHI-05, MHI-06, MHI-07, MHI-09)
4 STF-2 couplers
(coaxial disk rf window, 60f )
Cryomodule-C
FNAL (AES004, ACC011) cav.
DESY (Z108, Z109) cavities
4 TTF-III couplers
(cylindrical rf window, 40f )
E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing

6. RF Processing of Input Couplers
Cryomodule-C /KLY#1 (2MW)
Cryomodule-A /KLY#2 (5MW)
0.5 ms, 5 Hz, 500 kW
1.5 ms, 5 Hz, 200 kW
Aug. 25 ~ Sept. 07 (10 days)
E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing

7. RF Processing Time of Input Couplers
at room temperature
Cryomodule-A
(STF-2 couplers)
ave. processing time
~ 13 hours
20 hr
Cryomodule-C
(TTF-III couplers)
ave. processing time
~ 21 hours
20 hr .
Vacuum I/L ; 2.x10-4 Pa
E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing

8. Operational RF power level for 8-cavity operation
Stable operating Eacc (individual cavity operation)
Calc. ave. Eacc
C : 24 MV/m
A : 28 MV/m
C&A : 26 MV/m
0.5 ms
1.0 ms
After warm-up to an intermediate temperature due to the trouble of cryogenic system, deterioration of
vacuum pressure was suddenly occurred in A1 coupler, and operational RF power level was reduced.
E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing

9. Inspection of STF-2 Couplers after Disassembly
Cold couplers
E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing

10. Inspection of TTF-III Couplers after Disassembly
C1/ FNAL
C2/ FNAL
C3/ DESY
C4/ DESY
E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing

11. Calculated and Measured Static Heat Load
by N. Ohuchi (KEK)
E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing

12. Dynamic Loss Measurements in S1-G
by N. Ohuchi (KEK)
C-4
C-1
A-3
A-2
4 C Cavities
4 A Cavities
4 A Cavities 7
Cavities
Date
Nov. 17
Nov. 19
Nov. 23
Nov. 24
Nov. 25
Nov. 26
Nov. 30
Dec. 2
Dec. 3
Dec. 9
Dec. 10
Gradient
28 MV/m
25.2 MV/m
32.3 MV/m
38 MV/m
32 MV/m
Detune
20 .0 MV/m
26.9 MV/m
25.4 MV/m
20.4 MV/m
Dynamic Loss
0.84 W
1.44 W
2.8 W
4.8 W
2.6 W
2.7 W
6.9 W
9.6 W
Detuned Loss
0.09 W
0.18 W
0.7 W
1.8 W
1.2 W
0.5 W
4.6 W
0.2 W
2.5 W
1.6 W
Dynamic Loss at Cavity
0.75W
1.26 W
2.0 W
2.9 W
1.3 W
4.4 W
7.0 W
3.2 W Q0
8.8E9
4.3E9
4.2E9
6.5E9
C1=22.2
C2=18.9
C3=14.9
C4=24.3
A1=15.8
A2=37.6
A3=32.9
A4=21.4
C1=25.2
C2=NA
C3=17.6
C4=28.8
A1=15.3
A2=37.4
A3=32.4
A4=20.9
C1=20.1
C3=14.1
C4=23.0
A1=12.3
A2=30.4
A3=26.0
A4=16.7
Dynamic losses of KEK couplers was 9 times
larger than those of TTF-III couplers.
E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing

13. Dynamic RF Loss of TTF-III Input Couplers
by N. Ohuchi (KEK)
E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing

14. Dynamic RF Loss of STF-2 Input Couplers
by N. Ohuchi (KEK)
E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing

15. Temperature Distribution around 5K in A2 Cavity
E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing

16. Temperature Distribution around 80K in A1/A2 Cavity
E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing

17. Further studies in STF-2 couplers
　Reduction of static loss
　Reduction of dynamic loss
　Efficient cooling by thermal anchor
STF-2 input coupler for S1-G
Two input couplers
for QB-Cryomodule
0.8t SUS +
Ni strike plating (0.2um)
+ Cu plating (3um)
→ Ni/Cu alloy (high R)
Elimination
of bellows
(Coupler-B, 10um)
(Coupler-A, 5um)
Poor cooling to 5K
→ avoiding Ni-strike plating
E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing

18. Sample tests of Cu plating on Au strike plating1.
Gold strike plating of 0.2 um and Cupper plating of 3 um on 0.8t SUS pipe
2. After 800 oC Heat Treatment
3. After 1st heat cycle to 4.2 K
4. After 2nd heat cycle to 4.2 K
E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing

19. SUMMARY
Four TTF-III input couplers and four STF-2 input couplers were successfully conditioned and operated at high RF power of 100~450 kW in S1-G cryomodule.
Vacuum deterioration occurred in one STF-2 coupler.
Disassembly troubles happened in two TTF-III couplers.
Larger dynamic heat loads in STF-2 couplers than that in TTF-III couplers were observed.
Improvements of RF losses in STF-2 couplers are under going.
E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing

20. END Thank you for your attentions ! TTC meeting in Beijing
E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing

21. E. KAKO (KEK) ' Dec. 07
TTC meeting in Beijing