Dark Current and Multipacting in the Photocathode RF Guns at PITZ

For photocathode rf guns, the amount of dark current depends on the cavity surface as well as on the photocathodes. Smooth conditioning reduces the amount of dark current. Multipacting in the gun cavity changes the surface status of the cathodes and sometimes obstructs the gun operation because of vacuum interlocks. In this paper, dark current and multipacting features of an rf gun are presented including experimental and simulation studies.