• R. Nagai, R. Hajima, N. Nishimori
  JAEA/ERL, Ibaraki
• Y. Honda, T. Miyajima, T. Muto, M. Yamamoto
  KEK, Ibaraki
• H. Iijima, M. Kuriki
  HU/AdSM, Higashi-Hiroshima
• M. Kuwahara, T. Nakanishi, S. Okumi
  Nagoya University, Nagoya

A 500-kV, 10-mA pho­to­cath­ode DC gun has been de­signed and is now under fab­ri­ca­tion by the col­lab­o­ra­tion ef­forts of JAEA, KEK, Hi­roshi­ma Univ. and Nagoya Univ. The Cock­croft-Wal­ton gen­er­a­tor and the ce­ram­ic in­su­la­tor are in­stalled up­right in the SF6 tank. We have adopt­ed a mul­ti­ple-stacked cylin­dri­cal ce­ram­ic in­su­la­tor, be­cause this type of ce­ram­ic in­su­la­tor has shown good sta­bil­i­ty and ro­bust­ness at the 200-kV Nagoya po­lar­ized gun and the 250-kV JAEA FEL gun. The vac­u­um cham­ber, the guard-rings and the sup­port-rod elec­trode are made of ti­ta­ni­um alloy with very low out-gassing and ro­bust­ness to high volt­age per­for­mances. The Cock­croft-Wal­ton gen­er­a­tor, the ce­ram­ic in­su­la­tor, the vac­u­um cham­ber and the guard-rings have been as­sem­bled and a high-volt­age test has been suc­cess­ful­ly done with up to 550kV. The high-volt­age test and up-to-date sta­tus of the gun de­vel­op­ment will be pre­sent­ed in de­tail.

• S. Sakanaka, M. Akemoto, T. Aoto, D.A. Arakawa, S. Asaoka, A. Enomoto, S. Fukuda, K. Furukawa, T. Furuya, K. Haga, K. Hara, K. Harada, T. Honda, Y. Honda, H. Honma, T. Honma, K. Hosoyama, M. Isawa, E. Kako, T. Kasuga, H. Katagiri, H. Kawata, Y. Kobayashi, Y. Kojima, T. Matsumoto, H. Matsushita, S. Michizono, T.M. Mitsuhashi, T. Miura, T. Miyajima, H. Miyauchi, S. Nagahashi, H. Nakai, H. Nakajima, E. Nakamura, K. Nakanishi, K. Nakao, T. Nogami, S. Noguchi, S. Nozawa, T. Obina, S. Ohsawa, T. Ozaki, C.O. Pak, H. Sakai, H. Sasaki, Y. Sato, K. Satoh, M. Satoh, T. Shidara, M. Shimada, T. Shioya, T. Shishido, T. Suwada, M. Tadano, T. Takahashi, R. Takai, T. Takenaka, Y. Tanimoto, M. Tobiyama, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, K. Watanabe, M. Yamamoto, S. Yamamoto, Y. Yamamoto, Y. Yano, M. Yoshida
  KEK, Ibaraki
• M. Adachi, M. Katoh, H. Zen
  UVSOR, Okazaki
• R. Hajima, R. Nagai, N. Nishimori, M. Sawamura
  JAEA/ERL, Ibaraki
• H. Hanaki
  JASRI/SPring-8, Hyogo-ken
• H. Iijima, M. Kuriki
  HU/AdSM, Higashi-Hiroshima
• I. Ito, H. Kudoh, N. Nakamura, S. Shibuya, K. Shinoe, H. Takaki
  ISSP/SRL, Chiba
• H. Kurisu
  Yamaguchi University, Ube-Shi
• M. Kuwahara, T. Nakanishi, S. Okumi
  Nagoya University, Nagoya
• S. Matsuba
  Hiroshima University, Graduate School of Science, Higashi-Hiroshima
• T. Muto
  Tohoku University, School of Scinece, Sendai
• K. Torizuka, D. Yoshitomi
  AIST, Tsukuba

Fu­ture syn­chrotron light source using a 5-GeV-class en­er­gy re­cov­ery linac (ERL) is under pro­pos­al by our Japanese col­lab­o­ra­tion team, and we are con­duct­ing ac­tive R&D ef­forts for that. We are de­vel­op­ing su­per-bril­liant DC pho­to­cath­ode guns, two types of cry­omod­ules for both in­jec­tor and main su­per­con­duct­ing linacs, 1.3 GHz high CW-pow­er rf sources, and other im­por­tant com­po­nents. We are also con­struct­ing a com­pact ERL for demon­strat­ing the re­cir­cu­la­tion of low-emit­tance, high-cur­rent beams using those key com­po­nents. We pre­sent our re­cent progress in this pro­ject.