Nishitani, T.
(Tomohiro Nishitani)

THPOS21 Recent Results of the JAERI Energy-Recovery Linac FEL
Ryoichi Hajima, Hokuto Iijima, Nobuhiro Kikuzawa, Eisuke John Minehara, Ryoji Nagai, Nobuyuki Nishimori, Tomohiro Nishitani, Masaru Sawamura (JAERI/FEL, Ibaraki-ken)

A research program towards a high-power FEL utilizing an energy-recovery linac is carried forward at Japan Atomic Energy Research Institute (JAERI). In this paper, we summarize recent results of the research activity at the JAERI ERL-FEL, which include the reinforcement of the injector, replacement of the RF control system and so on.

THPOS23 JAERI 200 kV Electron Gun with an NEA-GaAs Photocathode
Tomohiro Nishitani, Ryoichi Hajima, Nobuhiro Kikuzawa, Eisuke John Minehara, Ryoji Nagai, Nobuyuki Nishimori, Masaru Sawamura, T. Yamauchi (JAERI/FEL, Ibaraki-ken)

The GaAs photocathode with negative electron affinity surface (NEA-GaAs) has been expected to be low emittance (<0.5 πmm・mrad) electron beam source. In order to generate low emittance electron beam required from ERL-FEL, we have started the developmental program of a 200keV electron gun with the NEA-GaAs photocathode for the first time in JAERI. An NEA surface has the problem that lifetime is limited by gun vacuum condition and by ion back bombardment between anode- and cathode-electrode. In order to long an NEA surface lifetime, the JAERI 200keV electron gun system consists of a 200kV DC-gun chamber on extreme high vacuum condition and an NEA activation chamber with load-lock system.