DC photoemission gun development for the compact ERL

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

The next generation ERL light sources require a high brightness and high current electron gun. We have developed a DC photoemission electron gun for the Japanese ERL light source project. This DC gun employs a segmented insulator with guard rings to protect the insulator from field emission generated from central stem electrode. We have successfully applied 500 kV on the ceramics with a cathode electrode in place and generated beam from the 500 kV gun at Japan Atomic Energy Agency (JAEA) in October 2012. The gun was transferred to the compact ERL (cERL) at KEK for commissioning of the cERL injector. Details of the 500 keV beam generation at JAEA as well as beam operational experience at the cERL will be presented.