A pseudospark cathode Cherenkov maser: theory and experiment

Abstract

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.

Cherenkov interaction and post-acceleration experiments of high brightness electron beams from a pseudospark discharge

“…To complement the experimental investigations of the Cherenkov maser, a three-dimensional numerical simulation code was developed [7,8]. The simulations show that the TM 01 mode at B21 GHz is amplified strongly, attaining a power of B3.4 kW at z ¼ 60 cm, whereas the power in the TM 02 mode at B55 GHz remains around its initial level.…”

Design of a 0.35 THz Extended Interaction Oscillator Based on Pseudospark-Sourced Sheet Electron Beam

“…In VEDs high quality intense electron beams are required as the frequency increases. This has resulted in the pseudospark (PS) discharge attracting a lot of attention as a promising source of high quality, high intensity electron beam pulses as the beam current densities of up to 10 8 A m -2 and brightness up to 10 12 A m -2 rad -2 have been reported [3][4][5][6][7]. A PS-sourced electron beam does not require the use of an external guide magnetic field as the beam is selffocused by ion channel focusing.…”

Effects of Tolerance Fabrication of Extended Interaction Oscillator Based on Pseudospark-sourced Sheet Electron Beam at 0.35 THz

“…Therefore a compact and simplified structure is desirable with the pseudospark-sourced (PS) electron beam an ideal cathode for the high power, high frequency source. This is because of the formation of an ion channel following the PS anode, which enables the beam to propagate with no need of a guiding magnetic field [3][4][5][6][7][8][9][10][11]. Among various VEDs, the EIO as a linear beam vacuum device has gained considerable attention as a promising millimeter wave oscillator due to its high gain per unit length and compact configuration [8][9][10][11].…”