STUDY OF THE COLD CATHODE RF ELECTRON GUN BASED ON DOPED DIAMOND FILMS AT CAEP

摘要

Diamond films, especially nitrogen doped ultra-nanocrystaline diamond (UNCD) films are considered as promising field emission cathodes because of their low threshold field as well as high thermal conductivity, high breakdown field and chemical inertness. At the present a half cell S-band RF gun which is expected to provide high current electron bunches for a compact THz-FEL facility has been constructed to study the field emission properties of diamond films at the Institute of Applied Electronics in CAEP. The films are deposited on a metallic base of molyb-denum by microwave plasma chemical vapour deposition (MPCVD) methods. After installed in the RF gun, an electric field of nearly 90 MV/m can be achieved on the surface of the films so as to obtain high current electron bunches. Here the basic concepts, the experimental setup and results are presented.