Pseudospark experiments: Cherenkov interaction and electron beam post-acceleration

Pseudospark (PS) discharge experiments to generate high-brightness electron beams have been carried out at the Strathclyde University, Glasgow, U.K. The PS-sourced electron beam has two phases, an initial 22-kV, 50-A hollow-cathode phase (HCP) beam of brightness 10/sup 9-10/ Am/sup -2/ rad/sup -2/ followed by a 200-V, 200-A conductive phase (CP) beam of brightness 10/sup 11-12/ Am/sup -2/ rad/sup -2/. The initial HCP beam from an eight-gap PS discharge was applied for the first time in a Cherenkov interaction between the electron beam and the TM/sub 01/ mode of a 60-cm long alumina-lined waveguide. A gain of 29/spl plusmn/3 dB was measured and an output power of 2/spl plusmn/0.2 kW in the frequency range 25.5-28.6 GHz. Another experiment was focused on the study of the propagation and post-acceleration of the CP beam from a three-gap PS discharge chamber. The beam was successfully accelerated from about 200 V to more than 40 kV.