Application of a pseudospark-generated electron beam to a 200GHz backward wave oscillator

Summary form only given. The pseudospark discharge is a form of low-pressure gas discharge, capable of generating extremely high currents within short rise times by means of a unique hollow cathode structure [1-2]. A high-quality electron beam is generated during the later phases of the discharge process, which possesses high current density and brightness as well as the ability to self-focus via ion channel focusing. This makes it an excellent electron beam source for millimetre-wave generation. Backward wave oscillators (BWOs) are simple, versatile sources of high frequency radiation which do not require the presence of a feed millimeter wave signal. A BWO using a sinusoidally corrugated slow-wave structure has been simulated using the particle-in-cell code MAGIC-3D and has been shown to generate microwave radiation at 200 GHz in the presence of a 0.8 mm cross-sectional diameter electron beam. This structure has since been manufactured and an output horn has been designed for use with the structure. Beam experiments with a 4-gap, 42 kV pseudospark discharge have shown an electron beam current of 4 A following traversal of the interaction region. Recent results in the generation of millimeter wave pulses from the 200GHz BWO will be presented.