JPSP-CAS co-operation in Superconducting RF of BEPCII Wang Guang-wei, Pan Wei-min, Sun YI ( 孙毅） RF group of IHEP Apr. 8, 2009

overall of SRF system of BEPCII

JSPS-CAS co-operation 500MHZ superconducting cavity Main parameter of SRF of BEPC-II Cavity voltage 1.5MV Beam power / Ring 130kW RF phase stability ±1º RF voltage stability ±1％ RF Station phase 0º - 720º 250KW RF amplifier JSPS-CAS co-operation 500MHZ superconducting cavity LLRF interlock emergency quench arc P+ P_ Low level control

Key time of the co-operation in SRF of BEPCII (2004-2009) 2004~May,2005 two superconducting cavities fabrication, processing, vertical test at KEK Jun. 2006 first high power horizontal test of SCC at china mainland in the history Aug. 2006 2×SCC installation into tunnel 2005~2008 LLRF & beam commissioning 2006~2009 IHEP coupler test at KEK

Cavity fabrication, processing, vertical test at KEK Cavity assembly at KEK HOM damper test

SC cavity was transported to tunnel after the final assembled

SCC Vertical test at KEK (Nov.2004~Feb.2005) IHEP: G.Wang, W.Pan, Y.Sun, Z.Li, Q.Ma had taken part in SCC vertical test at KEK ( Nov.2004~Feb. 2005 )

First high power horizontal test in IHEP (Jun.2006) RF voltage >2MV Q0 > 5×108 radiation of E cavity is decreased after high power RF aging Experts from IHEP,KEK,MELCO,SSRF taken part in the high power test

SCC high power test result: (Jun.2006) KEK: T.Furuya , K. Akai, S.Mitsunobu, MELCO: 荒川 雅德 SSRF: Liujf, Guq, Houht, IHEP: Wanggw, Panwm, Suny, Lizq, Maq, Xub, Lisp, Hek, Liuyp, Zhangc, Mal, Xuzx, wangjq, etc. East SCC West SCC Static loss 30W 27W Q0（2MV） 5.4×108 1.02×109 Q0（1.8MV） 9.8×108 1.28×109 Q0 1.7×109(1.5MV) 1.44×109(1.6MV) QL 2×105 1.92×105 RF Pulse aging 50Hz/duty 5% Cut off RF power in a quench SCC under RF pulse aging P- P + RF voltage Reflect power Input power RF waveform to SCC

BEPCII cavities was installed at tunnel (Aug.2006)

Prof. K. Akai at LLRF design meeting ( IHEP Apr. 2004 )

LLRF commissioning at first beam run (2006~2007) Prof. K. Akai help Input RF power Reflect power 1.89 to 2.5GeV SR-ring operation(24 hrs) Vc 1.3MV (East SCC)

High power test of IHEP coupler at KEK (in 2008)

IHEP coupler test results The power reached is 270kW. (April, 2008) (highest power level in china)

(Got helps from Prof. T. Furuya and Prof. S. Mitsunobu) Praperation works before the high power test of couplers fabricated by IHEP was doing at KEK (Got helps from Prof. T. Furuya and Prof. S. Mitsunobu) High pressure rinsing ( W.Pan, Q. Ma, T.Huang T. Furuya ,S. Mitsunobu )

Future co-operation suggestion Spare cavity of BEPCII ( it is now under the fabrication in china ) High power input coupler Digital Low-level RF

Paper list: W. Pan, Y. Sun, G. Wang, T. Furuya and S. Kurokawa, “Studies on Higher Order Modes　 in BEPC II Superconducting Cavity”, High Energy Physics and Nuclear Physics, Vol. 28, No. 3, March, 2004, pp 317-320. (2) Z. Li and C. Zhang, “Study of Heavily Damped SC RF Cavity”, High Energy Physics and Nuclear Physics, Vol. 27, No. 10, pp919-925, 2003. (3) T. Furuya, K. Akai, K. Hara, K. Hosoyama, A. Kabe, G. Katano, Y. Kojima, S. Mitsunobu, Y. Morita, H. Nakai and M. Yamaga, “Achievements of the Superconducting Damped Cavities in KEKB Accelerator”, Proc. of the 11th Workshop on RF-superconductivity, DESY, Germany, 8 – 12 Sept. 2003. (4) K. Akai, et al.,“RF Systems for the KEK B-Factory”, Nuclear Instruments and Methods in Physics Research, A 499, 2003, pp. 45-65. (5) W.M. Pan, G.W. Wang, Y. Sun, Z.Q. Li, H.Y. Lin, B. Xu, Q. Ma, T.M. Huang, P. Sha, “High Power conditioning of the Input Coupler for BEPCII Superconductor Cavity”, Proc of the 13th Workshop on RF Superconductivity, Beijing, China, 15-19 Oct. 2007. (6) Sun Yi , Wang Guangwei, Pan Weimin, Li Zhongquan, Ma Qiang, Lin Haiying, Li Shaopeng, He Kun, Liu Yaping, Huang Hong, Xu Bo, wang Qunyao, Huang Tongming, “Commissioning of BEPCII superconducting RF system”, Proc of the 13th Workshop on RF Superconductivity, Beijing, China, 15-19 Oct. 2007. (7) Yaping Liu, Li Shaopeng, He Kun, Sang Minjing, Ge Rui, Lv Chongwei, Bian Lin, Zhang Zhuo, “Cryogenic System for BEPCII Superconducting Cavity”, Proc of the 13th Workshop on RF Superconductivity, Beijing, China, 15-19 Oct. 2007. (8) Z.Q. Li, G.W. Wang, W.M. Pan, Y. Sun, S.P. Li, Q. Ma (IHEP). T. Furuya, S. Mitsunobu, K. Akai, Y. Yamamoto, Y. Kijima, M. Arakawa, Y. Okada, “Fabrication and Test of the 500MHz SC Modules for the BEPCII”, Proc of the 13th Workshop on RF Superconductivity, Beijing, China, 15-19 Oct. 2007. (9) G.W. Wang , W.M. Pan, Y. Sun, Z.Q. Li, G.Y. Zhao, H.Y. Lin, Y.F. Xu, H. Huang, Q. Ma, B. Xu, Q.Y. Wang, Y.P. Liu, P. Sha, T.M. Huang, R. Liu, R.H. Zeng, T. Furuya, S. Mitsunobu, K. Akai, “BEPCII RF system”, Proc of the 13th Workshop on RF Superconductivity, Beijing, China, 15-19 Oct. 2007.

Thanks to JSPS co-operation! Summary SRF system of BEPCII is one of the co-operation flowers between JSPS-CAS (KEK-IHEP) , just same as the blooming SAKURA at YU YUAN TAN park of BEIJING. 2004~2006, two SC cavities had been fabricated, processed, and tested in Japan; The first high power test had been successfully carried out in 2006 at IHEP. Two SRF systems above 1.5MV voltage have contributed to e+/e- collision beam over 2×500mA, and 2.5GeV/250mA of 100KW beam power in SR mode Since the end of 2006. thank Prof. S.Kurokawa for his great contribution to the superconducting cavity co-operation between IHEP and KEK, thank to Professors: K.Akai, T.Furuya, S.Mitsunobu, K.Hosoyama, for their kind help. Thanks to JSPS co-operation!