• H. Yoshikawa, H. Sakaki, T. Suzuki
  JAEA, Ibaraki-ken
• S.F. Fukuta
  MELCO SC, Tsukuba
• H. Ikeda
  Visual Information Center, Inc., Ibaraki-ken
• T. Ishiyama
  KEK/JAEA, Ibaraki-Ken
• Y.I. Itoh, Y. Kato, M. Kawase, H. Sako, G.B. Shen, H. Takahashi
  JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
• S.S. Sawa
  Total Saport System Corp., Naka-gun, Ibaraki

Linac of J-PARC began to operate in November, 2006, and a achieved an initial performance in January, 2007. Afterwards, the beam supply to RCS begins, and it is operating extremely well with stability up to now. Here, the evaluation for comparison of the design and realities of architecture and performance of the LINAC control system are shown. Especially, the conceptual idea of function arrangement in the hierarchy of the control system architecture is shown. Now, the linac control system is in the second phase for the high power beam and reducing the beam loss, and the analysis of the system response identification for the high precision beam control is started.

• Y. Kato, A. Fujita, Y. Hama, T. Hirose, C. Igarashi, A. Masuda, A. Murata, T. Nomoto, K. Sakaue, T. Suzuki, M. Washio
  RISE, Tokyo
• H. Hayano, T. Takatomi, N. Terunuma, J. Urakawa
  KEK, Ibaraki
• Y. Kamiya
  University of Tokyo, Tokyo
• S. Kashiwagi
  ISIR, Osaka
• M. Kuriki
  HU/AdSM, Higashi-Hiroshima
• R. Kuroda
  AIST, Tsukuba, Ibaraki

Funding: Work supported by MEXT High Tech Research Project HRC707, JSPS Grant-in-Aid for Scientific Research (B)(2) 16340079
At Waseda University, we have been developing a high quality electron source based on photo-cathode rf gun which has a Cs-Te cathode with high quantum efficiency. Until now, at the Waseda University we have succeeded the soft X-ray generation via inverse-Compton scattering and pulse radiolysis system for studying the early processes of radiation chemistry with electron beams generated by copper cathode rf gun. Cs-Te rf gun is expected to generate higher charge electron bunches with a low emittance than a copper cathode because of its high quantum efficiency and also the high-quality multi-bunch electron beams. That enables us to extend the range of electron beam parameters for our application experiments. However, a Cs-Te cathode has a short life compared with a copper, so it has to be exchanged occasionally, thus we have developed a new rf-gun cavity which can be attached the compact cathode load-lock system. Moreover, we improved the design of an existing rf-gun cavity for the reduction of the dark current and the higher electric field. In this conference, the performance of the improved cavity and the result of electron beam generation experiments will be reported.