• W.H. Hwang, K.M. Ha, K.R. Kim, S.H. Kim, S.H. Kim, S.S. Park, Y.G. Son
  PAL, Pohang, Kyungbuk
• M. Yoon
  POSTECH, Pohang, Kyungbuk

Pohang Accelerator Laboratory, PAL, has been proposing a 0.1 nm SASE FEL. This machine will be designed with an S-band rf linear accelerator to produce a 10.053 GeV electron beam. The output power of klystron is 80 MW at the pulse width of 4 μs and the repetition rate of 30 Hz. The beam energy spread is 0.037%(rms), and rf phase stabiltity is 0.1 degrees(rms). The SASE FEL needs the modulator stability of 0.1%. We developed the modulator DeQing system to use the existing modulator systems that are “line type modulator system”. And we also are considering an inverter power supply to meet the required specification of the FEL machine. We are developing the phase amplitude detection system(PAD) and phase amplitude control(PAC) system to obtain the required rf stability. This paper describes the rf system for PAL XFEL(PxFEL).