First beam measurements of the S-Band photocathode radio-frequency gun at Tsinghua University

During the last decades, photocathode rf gun has been proven to be successful in generating the high brightness election beam (similar to InC,similar to 1 pi mmmrad,similar to 1 ps) which is required by the ILC, XFEL, Thomson scattering x-ray source, etc. A photocathode if gun system is built to develop electron source for the Thomson scattering x-ray source at Accelerator Laboratory of Tsinghua University. The system consists of a BNL/ATF-type 1.6 cell S-band rf cavity, a solenoid for emittance compensation, a laser system and some simple equipments for beam diagnosis. The first beam measurements of the photocathode if gun, including the dark current, transverse beam profile, charge and quantum efficiency, are reported.