Research and fabrication of the photocathode used in DC-SC photocathode RF electron gun

DC-SC photocathode RF electron gun is the new injector based on the laser-driven superconducting RF gun. It has been designed and is on the way of operation at Beijing University, in order to produce the beam with high average current required by SASE FEL experiments. High quantum efficiency cesium telluride photocathodes are fabricated in two methods, and the results are compared and analyzed. To resolve the key problems in the preparing process, such as the super high vacuum, the accurate controlling of Cs flux, the temperature of cathode, a new photocathode preparation chamber has been designed for the DC-SC electron gun. (author)