• F.S. He, J. Dai, J.K. Hao, S. Jin, Y.M. Li, L. Lin, K.X. Liu, X.Y. Lu, S.W. Quan, W. Xu, B.C. Zhang, K. Zhao, F. Zhu
  PKU/IHIP, Beijing

Peking University is striving for constructing a superconducting radio-frequency accelerator test facility (PKU-SETF) to provide coherent radiations [1]. A cryomodule consisting of a China made 9-cell TESLA type cavity was designed and constructed for this purpose, which is expected to provide 15-20 MeV energy gain at an operating temperature of 2K. Some technical issues in the manufacturing progress are reported, including the tungsten inert gas (TIG) welding of the LHe vessel and the superconducting cavity, the demagnetization of the vacuum vessel made of pure iron, and the manufacturing of the main power coupler.

• Z.Y. Yao, C. Chang, J.K. Hao, F.S. He, Y.M. Li, L. Lin, K.X. Liu, X.Y. Lu, S.W. Quan, B.C. Zhang, K. Zhao, F. Zhu
  PKU/IHIP, Beijing
• L. Yang
  Peking University, School of Physics, Beijing

Spoke cavities have been developed and have apparent advantages for high current proton accelerator based on superconductivity at low and medium energy region. As the research and the technical reserve, Peking University has started the R&D program of single spoke cavity (SSC). The work is proposed to do beam load experiment on the HI-13 Tandem at CIAE. The maximum kinetic energy of proton beam is 26MeV, and the frequency of the chopper for superconducting is 150MHz. It leads us to the choice of a 450MHz and β=0.2 single spoke cavity. In this paper, the RF design, mechanical study, fabrication arts, tolerance analysis, and room temperature RF test is presented.

• F. Wang, F.S. He, L. Lin, K. Zhao
  PKU/IHIP, Beijing

As part of the updated DC-SC injector, a 3.5cell cavity has been fabricated at Peking University, which includes two Coaxial High Order Mode (HOM) couplers. The effect of the HOM couplers has been studied by numerical simulation and measurement. The results are highly uniform and show that the two couplers do effectively damp the HOMs.