1. IHEP ILC Cavity Status Jiyuan Zhai (IHEP)
on behalf of the IHEP ILC SRF Team
LCC-ILC Cavity Meeting
March 4, 2015

2. ILC Test Cryomodule
Second LN2 cool down test in Feb., with new cryogenic connections (welding instead of many seals)
Isolation vacuum improved: 1E-1 Pa => 6E-6 Pa, with larger TMP
Cavity vacuum improved: 4E-5 Pa => 8E-8 Pa, with large ion pump and NEG in beam tube
Confirm 2K line cold leak inside cryomodule. Plan to disassemble the module, find and repair the leak (indium/copper seals? TIG weld? helium vessel?), reassemble and 80K cool down test again in mid 2015
Cavity further expanded 0.7 mm (will press the cavity after disassembly and add mechanical stopper on the tuner)

3. Mechanical Stopper for Cavity Expansion (KEK STF)
Several tuner types can both press and stretch cavity (Saclay2 tuner, CEBAF upgrade)

4. HOM1 Cross Talk with Input Coupler
Qt: 7E11 (VT)
s21 (input coupler in)
Pickup out: dB
HOM1 out: dB
HOM2 out: dB

5. Cavity R&D TESLA-like 9-cell Cavity (IHEP-03, FG)
IHEP-KEK collaboration; EBW completed in end 2014
Tumbling at IHEP in March-April, process and test at KEK in May-June
TESLA 9-cell Cavity (HER-01, FG)
with full end groups, plan to complete in end 2015
A spoke024 cavity welded by IHEP EBW machine in 2014, => 4+4 spoke
High Q study by nitrogen doping
1.3 GHz single cell using IHEP’s new furnace

6. New Cryogenic Plant in Operation
Tested in Jan. 2015
Refrigeration: K
Liquefaction:
302 L/h
Mixed mode:
352 W L/h
Total pumping:
Pa (200 2 K)
System now in operation for China ADS injector TCM1 (two spoke012 cavities with solenoids, 10 mA CW), and later for ADS cryomodules (14 spoke cavities), ILC test cryomodule, FEL-ERL test facility cryomodules, and vertical test stand)

7. New Vertical Test Stand
Inner diameter: 850 mm
Magnetic shield inside dewar
Effective diameter: 800 mm
Various cavities: 1.3 GHz MHz
Start closed-loop 2K vertical test
in mid 2015

8. New RF Power Source 1.3 GHz 5 MW (1.6 ms pulsed) klystron
Marx modulator
Both to be delivered in end March 2015
Waveguides, circulator, loads etc. (funded soon)