• R. Kuroda, M. Koike, K. Yamada
  AIST, Tsukuba, Ibaraki

A compact THz-FEL has been developed based on a laser photocathode rf gun system at AIST. The rf gun has been improved using a Cs2Te photocathode with a compact load-lock system. The multi-bunch electron generation has been performed with the rf gun and the multi-pulse UV laser system. The undulator has been designed to generate THz-FEL. The preliminary experiment of THz applications has been carried out using a coherent synchrotron radiation in the THz region with 40 MeV electron beam. In this conference, we will report a present status and results of the experiment.

• H. Zen, M. Adachi, K. Hayashi, M. Katoh, J. Yamazaki
  UVSOR, Okazaki
• M. Hosaka, M. Koike, Y. Taira, Y. Uno, N. Yamamoto
  Nagoya University, Nagoya
• T. Tanikawa
  Sokendai - Okazaki, Okazaki, Aichi

At the UVSOR storage ring, free electron laser (FEL) have been studied for more than a decade. After the upgrade of accelerator components in 2003, FEL lasing around 199 nm [1] has been achieved. In these years, several application experiments of the FEL in deep UV region have been carried out. A feedback alignment system of the optical resonator has been developed to improve long term stability of the laser power for user experiments. To promote application experiments more extensively, now we have two upgrade plans. One is FEL lasing with top-up operation in order to maintain a high beam current and then a high out-coupled power. The other is upgrade of the optical klystron to have higher gain at deep UV region. These two upgrades will allow us to attract more users to our FEL.

[1] M. Hosaka, “Lasing below 200 nm at the UVSOR-II FEL,” UVSOR Activity Report 2007.