Generation of broadband terahertz radiation using a backward wave oscillator and pseudospark-sourced electron beam

摘要

This paper presents for the generation of a small size high current density pseudospark (PS) electron beam for a high frequency (0.2 THz) Backward Wave Oscillator (BWO) through a Doppler up-shift of the plasma frequency. An electron beam ～1 mm diameter carrying a current of up to 10 A and current density of 10~8 A m~(-2), with a sweeping voltage of 42 to 25 kV and pulse duration of 25 ns, was generated from the PS discharge. This beam propagated through the rippled-wall slow wave structure of a BWO beam-wave interaction region in a plasma environment without the need for a guiding magnetic field. Plasma wave assisted beam-wave interaction resulted in broadband output over a frequency range of 186-202 GHz with a maximum power of 20 W.