Generation of a 500-keV electron beam from a high voltage photoemission gun

直流光陰極電子銃からの500keV電子ビーム生成

西森 信行; 永井 良治; 松葉 俊哉; 羽島 良一; 山本 将博*; 宮島 司*; 本田 洋介*; 飯島 北斗*; 栗木 雅夫*; 桑原 真人*

Nishimori, Nobuyuki; Nagai, Ryoji; Matsuba, Shunya; Hajima, Ryoichi; Yamamoto, Masahiro*; Miyajima, Tsukasa*; Honda, Yosuke*; Iijima, Hokuto*; Kuriki, Masao*; Kuwahara, Makoto*

High-brightness and high-current electron guns for the future light sources such as energy recovery linac light sources and high repetition rate X-ray free electron lasers require exit beam energy of 500 keV or more to reduce space charge induced emittance growth in a drift space from the gun exit to the following superconducting accelerator entrance. At Japan Atomic Energy Agency, we have developed a DC photoemission gun employing a segmented insulator to mitigate the field emission problem, that is a major obstacle for the DC gun from being operated at 500 kV or more. Recent results of generating 500 keV electron beam with current up to 1.8 mA is presented.