Photoemission Properties of LaB6 and CeB6 Under Various Temperature and Incident Photon Energy Conditions

Abstract

Photoemission properties of LaB₆ and CeB₆ were investigated at various cathode temperatures and different wavelengths of excitation laser to study for application of electron gun, especially for RF injector of infrared FEL facilities. It was found that the LaB₆ had higher photoemission property than CeB₆ at the same cathode temperature. In addition, LaB₆ can emit a measurable photoemission current being irradiated by laser with energy below work function at the cathode temperature higher than 1400 K. With increasing laser energy (over work function), a photoemission dependency on cathode temperature was getting lower. As the result, LaB₆ is revealed to have better properties than CeB₆ since LaB₆ has higher quantum efficiency than CeB₆ at same temperature.