• J.Y. Zhai, J.P. Dai, L. Dong, J. Gao, Z.D. Guo, Z.Q. Li, L.L. Men, Q.Y. Wang
  IHEP Beijing, Beijing
• J.Z. Chen, J.Q. Qiao
  HJL, Beijing
• J.X. Wang, H. Yu, H. Yuan
  BIAM, Beijing
• W.P. Xie
  Ningxia Orient Tantalum Industry Co., Ltd., Dawukou District, Shizuishan city
• T.X. Zhao
  IHEP Beiing, Beijing

The combination of the low-loss shape and large grain niobium material is expected to be the possible way to achieve higher gradient and lower cost for ILC 9-cell cavities. As the key component of the 'IHEP 1.3 GHz SRF Accelerating Unit and Horizontal Test Stand Project', a low-loss shape 9-cell cavity using Ningxia large grain niobium has been fabricated and surface treated at IHEP and will be tested at KEK. The fabrication procedure, surface treatment recipes as well as the SRF facilities are presented in this paper.

• H. Yu
  SSRF, Shanghai
• M. Chen, Z.Q. Feng, H.T. Hou, J.F. Liu, Z.Y. Ma, D.Q. Mao, B. Yin
  SINAP, Shanghai

To investigate the higher order mode(HOM) damping in the higher harmonic cavity for Shanghai Synchrotron Radiation Facility(SSRF) when using HOM absorbers,simulations have been done for changing the position and the length as well as the thickness of ferrite of HOM damper. The best values under which the Q value of HOMs can be greatly lowered and the impedance of harmonic cavity will be trapped in the impedance threshold have been found.