Slow-wave Structure for the Millimeter-band Backward-wave Oscillator Based on the Pseudospark-source Electron Gun

Nowadays vacuum electron devices still remain the main sources of high power coherent and broadband millimeterwave radiation. Among electron beam sources the pseudospark discharge can be distinguished as a promising pulsed plasma electron beam source. The reason is that the pseudospark discharge sourced electron beam has the ability to self-focus due to the unique discharge structure and the formation of the ion channel generated by the beam front. The ion channel enables the electron beam to propagate and eliminates the need for a guiding magnetic field. Therefore the development of compact and high-power vacuum electron devices utilizing a pseudospark discharge based hollow cathode electron gun is one of the promising trends. Here the results of the design, optimization and development of a pseudospark-based high-current-density sheet electron beam source are presented. A slow-wave structure for the backward-wave oscillator driven by a pseudospark-sourced sheet electron beam was also designed and numerically studied. Preliminary results of numerical simulations of electrodynamic characteristics of the suggested slow-wave structure are shown. We are going to use a CNC-micro milling based technological approach to microfabricate the designed slow-wave structure. The first steps of microfabrication results are also presented.