Development of a 500-kV photocathode DC gun for ERLs

西森 信行; 永井 良治; 山本 将博*; 本田 洋介*; 宮島 司*; 飯島 北斗*; 栗木 雅夫*; 桑原 真人*; 奥見 正治*; 中西 彊*; et al.

Journal of Physics; Conference Series, 298, p.012005_1 - 012005_6, 2011/06

https://doi.org/10.1088/1742-6596/298/1/012005

An electron gun capable of delivering high current and high brightness electron beam is indispensable for ERL light sources. A high voltage photocathode DC gun is a promising gun for such new light sources. It is however difficult to apply DC high voltage on a ceramic insulator with a rod supporting cathode electrode because of field emission from the rod. In order to mitigate the problem, we have employed a segmented insulator with rings which guard the ceramics from the field emission. We have recently succeeded in applying 500-kV on the ceramics for eight hours without any discharge. Our recent development will be presented at the workshop.