1. 2 nd Workshop of the IHEP 1.3 GHz SRF R&D Project and 2nd IHEP-KEK 1.3 GHz SRF Meeting Opening Remark J. Gao December 2-3, 2009, IHEP, Beijing, China

2. The aim of this workshop and meeting 1.Review the annual progress of IHEP 1.3GHz SC project and next year plan 2.STF status 3.Collaboration between IHEP and KEK on 1.3GHz SC R&D items and schedule 4.Discussion on IHEP new SC lab

3. Chairman: Y.L. Chi Chairman: H. Hayano Chairman: J. Gao

4. The key technical issues 1.1.3GHz 9cell SC cavity surface treatment and vertical test (kek) 2.1.3GHz 9cell SC cavity final design issues (RF calculation, magnetic shielding, helium vessel…) 3.Tuner and LLRF design and fabrication 4.Main coupler design, fabrication and test 5.Cryomodule design and fabrication 6.SC lab facility development (including vertical cryostat, cavity inner surface inspection, T-Mapping, … ） 7.ERL SC cavity issues

5. Some comments

6. Yield Plot The gradients for DESY data were off by +2MV/m Not 08/09: large component of 2007, and very small component of 2009 Not 1 st or 2 nd test: instead, last (DESY) or best (JLab) Included cavities fabricated by ACCEL, ZANON, AES, JLab-2, KEK-Ichiro This is not the ideal data selection from which to infer a production yield Revised version (corrected only for mistakes) - same data shown 11 / 39 1 st test 13 / 39 2 nd test 7 / 39 3 rd test 3 / 39 4 th test 3 / 39 5 th test 1 / 39 8 th test Old version, shown at PAC, 2009

7. Standard Process for Yield Plot Standard Cavity Recipe FabricationNb-sheet (Fine Grain) Component preparation Cavity assembly w/ EBW (w/ experienced venders) Process1st Electro-polishing (~150um) Ultrasonic degreasing with detergent, or ethanol rinse High-pressure pure-water rinsing Hydrogen degassing at > 600 C Field flatness tuning 2nd Electro-polishing (~20um) Ultrasonic degreasing or ethanol High-pressure pure-water rinsing Antenna Assembly Baking at 120 C Cold Test (vert. test) Performance Test with temperature and mode measurement (1 st / 2 nd successful RF Test) 7

8. Comparison ‘Old’ vs ‘New’ Yield Plots Old New

9. S1 Goal: Reached at DESY PXFEL1 reported by H. Weise, at SRF-09 Average field gradient at CMTB : > 31.5 MV/m Note: DESY prepared cavities and assembled with the cryomodule cold mass contributed by IHEP for XFEL prototype

10. Global Plan for SCRF R&D Year 0720082009201020112012 Phase TDP-1TDP-2 Cavity Gradient in v. test to reach 35 MV/m >> Yield 50% >> Yield 90% Cavity-string to reach 31.5 MV/m, with one-cryomodule Global effort for plug-compatible string (DESY, FNAL, INFN, KEK) System Test with beam acceleration FLASH (DESY)NML (FNAL) STF2 (KEK) Preparation for Industrialization Mass Production Technology R&D 10

11. TTF/FLASH 9mA Experiment XFELILCFLAS H design 9mA studies Bunch charge nC13.213 # bunches3250262 5 7200 * 2400 Pulse length ss 650970800 CurrentmA5999 Full beam-loading long pulse operation  “S2” Stable 800 bunches, 3 nC at 1MHz (800  s pulse) for over 15 hours (uninterrupted) Several hours ~1600 bunches, ~2.5 nC at 3MHz (530  s pulse) >2200 bunches @ 3nC (3MHz) for short periods Stable 800 bunches, 3 nC at 1MHz (800  s pulse) for over 15 hours (uninterrupted) Several hours ~1600 bunches, ~2.5 nC at 3MHz (530  s pulse) >2200 bunches @ 3nC (3MHz) for short periods

12. BXFEL-ERL Test Facility L-Band （ 1.3 GHz ） Eacc ~ 20 MV/m 、 Energy gain ~ 60 MeV, Current 10 mA

13. Main Parameter of ERL Test Linac 模 式 ERL / FEL 能 量 (MeV) 65 / 77 电 流 (mA) 10 (ERL) 束流能散度 ≤ 0.3 % / 1% 归一化发射度 ≤ 3 mm mrad 注入器能量 (MeV) 5 / 20 束团重复频率 130 MHz / 13 Hz 电场梯度 (MV/m) 16 ~ 20 相位 (degree) 0 / -15 束团电量 (pC) 77 pC / 1 nC 主加速器腔数 4 单腔输入功率 (kW) 15~20

14. Have a good discussion and enjoy our research works and collaboration! Thanks