A pseudospark cathode Cherenkov maser: theory and experiment

The pseudospark discharge offers the possibility of producing electron beams which are very attractive for use in high-power microwave generation. A pseudospark-based Cherenkov maser amplifier is currently under development at Strathclyde University. The electron beam source for this maser is a multi-gap pseudospark discharge. Preliminary results from recent Cherenkov maser experiments and a comparison with a numerical simulation are presented. A microwave pulse of 100 ns duration and approximately 10 kW peak power was generated by a 80 kV, 20 A beam passed through an alumina-lined waveguide when the interaction was allowed to start up from noise, which appeared to originate from the pseudospark discharge. Simulations agree well with the experimental results when a beam energy spread of 1.5% is assumed.