DEVELOPMENT OF A PHOTOCATHODE DC GUN AT JAEA-ERL

An electron gun producing an e-beam with high- brightness and high-average current is a key component to realize a next-generation X-ray light source based on an energy-recovery linac (ERL). In JAEA, we are developing a photocathode DC gun for a future ERL light source. The DC gun is operated at 250 kV and 50 mA at maximum, and equipped with a load-lock chamber for cathode prepa- ration. In order to keep small emittance at high current op- eration, we adopt new type of semiconductor photocathode such as AlGaAs and superlattice. In this paper, we present the status of the gun development and future plans towards the ERL test facility to construct in collaboration with KEK and other institutes.