1. for the FNAL/ANL, JLab, and Cornell cavity teams
Americas Report
C.M. Ginsburg (FNAL)
for the FNAL/ANL, JLab, and Cornell cavity teams
S0 Meeting 12.July 2011

2. JLab Status RG
July 8, 2010

3. Ginsburg S0-Americas Report
9-cell Cavities
TB9AES011 first test after completing S0 processing steps: 36 MV/m at Q0 6E9, limited by radiation
TB9AES006 first test after FNAL CBP 100 um, [no light EP], vacuum furnace heat treatment, EP 35 um, 120Cx48hr bake: 36 MV/m at Q0 > 1E10, limited by quench.
Previous performance at JLab: 14 MV/m with limiting cell 5 HAZ pits 300 um and 500 um; 2nd pass limit 22 MV/m after standard EP
DESY 9-cell cavity hydroformed-with-seamless-tube (3x3), collaboration with FNAL and industrial partners, and final EBW at JLab
RF test following 2nd light EP: 20 MV/m at Q0 1.2E10, appears to be multipacting limited
IHEP-01 cavity processing at testing started with IHEP visitor Jiyuan Zhai working together with JLab colleagues.
TB9RI023 (heavy EP at RI) processing and testing started.
TB9NR001 second EP processing and testing is planned.
12.July 2011
Ginsburg S0-Americas Report

4. Cornell ILC activities
F. Furuta 12 July 2011
Inspection was done for ACCEL9 after last VT (max Eacc was 26MV/m).
No visible features or defects were found on quench location predicted by OST and other RF surface.
Next slide is brief history of ACCEL9. Re-oxipolish and RF test are planned.
The same procedures done on ACCEL9 will be applied on a single-cell cavity, NR1-2. This cavity is limited around 25MV/m so far. Some features were found on equator EBW seam and RF surface of NR1-2.
Tumbling is ongoing, then VEP + HT + oxipolish are planned.
New CBP machine will be moved to Newman lab, it will be available in this month.

5. Brief history of A9 Cornell ILC activities, F. Furuta 12July2011 VT
Cavity
Date
Process
Eacc max
Qo at Eacc max 1 A9
15-Aug-07
VEP+USC+HPR+Bake
26.6
7.64E+09 2
15-Sep-07
26.3
8.82E+09 3
4-Feb-09
25.3
3.53E+09 4
13-Mar-09
re-HPR
25.7
6.53E+09 5
8-Mar-11
+Oxipolish+USC+HPR+Bake
36.2
4.29E+09 6
14-Apr-11
25.6
1.09E+10

6. Inspection of NR1-2 Feature-2 Feature-1
Cornell ILC activities, F. Furuta 12July2011
Inspection of NR1-2
Feature-1
Feature-2

7. Ginsburg S0-Americas Report
FNAL/ANL Update
CM1 tests ongoing – all available cavities (7 of 8) were powered simultaneously
Plans underway for CM2 assembly – substantially affects other work
Horizontal test stand
6 cavities are ready in the string assembly
TB9RI024 had high field emission at HTS, perhaps due to poorly clocked flange assembly requiring significant manipulation of bellows. To be re-HPR’d and retested at HTS
Vertical qualification
Several 1-cell tests in pursuit of general R&D and vendor qualification – to be reported at SRF11
AES002 (dressed with helium pipe cut off) – after 120C bake at JLab and dressed-EP at FNAL/ANL
Approximately reaches the ILC gradient – heat flow restriction – reaches 36 MV/m at lower helium bath temperature
Next plans: TB9AES012 and TB9ACC012 (tumbled)
12.July 2011
Ginsburg S0-Americas Report

8. AES002 (dressed, no helium pipe) Update
The 120°C bake has eliminated the high-field Q-drop, and improved low-field Q0. (2.2 x 1010, up from 1.7 x 1010). Cavity now reaches 31 MV/m (quench limited) at 2K, and remains FE-free. Difficulty in obtaining accurate data at higher fields (loss > 100W) due to inefficient heat transfer through He vessel supply pipe.

9. Ginsburg S0-Americas Report
CM2 String Assembly
Shown: 4 cavities in string on July 1. Currently 6 are assembled.
12.July 2011
Ginsburg S0-Americas Report

10. Scenario 1: “best performance” CM2x
Now
Five HPR and HT preps
TB9RI018
TB9AES009
TB9AES010
TB9AES008
TB9ACC016
ACCEL8 (backup)
TB9AES007 (backup)
Four more good horizontal tests
TB9RI019
TB9RI018
TB9RI024 – HPR and re-HT
TB9RI027
12.July 2011
Ginsburg S0-Americas Report