Author: Kato, R.
Paper Title Page
Broadband THz FEL Oscillator via Resonant Coherent Diffraction Radiation at ERL Test Accelerator in KEK  
  • Y. Honda, A. Aryshev, R. Kato, T. Miyajima, T. Obina, M. Shimada, R. Takai, N. Yamamoto
    KEK, Ibaraki, Japan
  An Energy Recovery Linac can produce a low emittance and short bunch beam at a high-repetition rate. A test accelerator, compact-ERL, has been operating in KEK for development works of technologies related to ERL and CW-Superconducting accelerators. One of the promising applications of such a short bunch beam is a high-power THz radiation source produced by a coherent radiation. When a charged particle beam passes close to a conductive target, a radiation called diffraction radiation is produced. If the target mirrors form an optical cavity whose fundamental frequency matches the repetition frequency of the beam, the radiation resonates in the cavity, resulting in extracting a huge radiation power determined by the loss of the cavity. When the cavity is designed to be zero carrier envelope offset, all the longitudinal modes excite at the same time. This situation can be understood as an undulatory-less broadband FEL oscillator. We plan to perform an experiment of the resonant coherent diffraction mechanism in the return-loop of the compact-ERL. We report the design of the experimental setup to be installed in the summer of 2017.