• J. Gao, S.Y. Chen, Y.L. Chi, J.P. Dai, J. Gu, M. Hou, K.X. Huang, T.M. Huang, S.P. Li, Z.Q. Li, Q. Ma, W.M. Pan, Y. Sun, G.W. Wang, Z.X. Xu, J. Yu, J.Y. Zhai
  IHEP Beijing, Beijing
• L.Q. Liu, W.H. Lu, T.X. Zhao
  TIPC, BeiJing

Funding: NSFC 10525525

With the aim to develop 1.3 GHz superconducting radio-frequency (SCRF） technology in the frame of ILC collaboration, IHEP has started a program to build a SCRF Accelerating Unit. This unit contains a 9-cell 1.3 GHz superconducting cavity, a short cryomodule, a high power input coupler, a tuner, a low level RF system and a high power RF source, etc. This program also includes the SCRF laboratory upgrade, which will permit the unit to be built and tested at IHEP. We will use this unit as a horizontal test stand for many 9-cell cavities and other components (e.g. input couplers, tuners), as in Europe and North America. In this paper, we report the recent R&D status and the future plan of this program.

• J.R. Zhang, J.P. Dai, M. Hou, G. Pei
  IHEP Beijing, Beijing
• Q. Gu, M.H. Zhao, S.P. Zhong
  SINAP, Shanghai

RF deflectors can be used for bunch length measurement with high resolution. This paper describes the completed S-band travelling wave RF deflector and the bunch length measurement of the electron beam produced by the photocathode RF gun of Shanghai DUV-FEL facility. The deflector’s VSWR is 1.06, the whole attenuation 0.5dB, and the bandwidth 4.77MHz for VSWR less than 1.1. With laser pulse width of 8.5ps, beam energy of 4.2 MeV, bunch charge of 0.64 nC, the bunch lengths for different RF input power into the deflector were measured, and the averaged rms bunch length of 5.25 ps was obtained. A YAG crystal is used as a screen downstream of the deflector, with the calibrated value of 1pix =136um.