A Hybrid Laser-driven E-beam Injector Using Photo-cathode Electron Gun and superconducting Cavity

A laser-driven photo-cathode electron gun capable of producing pulsed electron beams of 100 KeV with a duration of 35 ps was constructed as a continuing effort towards a high-brightness superconducting RF injector. Various species of photo-cathodes can be obtained either by ion implantation, CVD or ion enhanced deposition in the preparation chamber attached to the injector. A number of photo-cathodes were tested in the light of enhancing the compatibility with the Nb cavity. At the same period, two sets of China made Nb cavities were successfully constructed and tested. As the next step, a hybrid photo-injector, using a DC laser-driven electron gun and one (beta<1) plus three (beta=1) superconducting cavities operating under 2 K is to be constructed. The design of the hybrid injector and possible production of the polarised electron beam from it are also discussed.