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Plasma Sci. Technol. ›› 2019, Vol. 21 ›› Issue (4): 044007.

• The 2018 Asia-Pacific Conference on Plasma and Terahertz Science (APCOPTS) • Previous Articles     Next Articles

E-beam generation in discharges initiated by voltage pulses with a rise time of 200 ns at an air pressure of 12.5–100 kPa

Victor TARASENKO 1,2, Dmitry BELOPLOTOV 1, Mikhail LOMAEV 1,2 and Dmitry SOROKIN 1   

  

  1. 1 Institute of High Current Electronics, Siberian Branch, Russian Academy of Sciences, Tomsk 634055, Russia
    2 National Research Tomsk State University, Tomsk 634050, Russia
  • Received:2018-10-22 Published:2019-01-25
  • Supported by:

    The work was performed by grants RFBR #18-52- 53003_GFEN_a.

Abstract:

The effect of air pressure (12.5, 25, 50, and 100 kPa) on the generation of runaway electron beams in a non-uniform electric field when applying voltage pulses (≈35 kV) with a rise time of ≈200 ns has been studied. The results show that the discharge has various stages: streamer, diffuse, and spark. Initially, a wide streamer develops in the gap and a diffuse discharge is formed. A spark is formed ≈100 ns after the breakdown. The current pulse of a supershort avalanche electron beam (SAEB) was measured with a collector at various pressures of air. Experiments show that there are two modes of generation of runaway electrons. At an air pressure of 25–100 kPa, a single SAEB current pulse with a full width at half-maximum (FWHM) of 120–140 ps is observed. At the air pressure of 12.5 kPa, two current pulses of the electron beam are observed. FWHM of the first and second current pulses are ≈140 ps and ≈300 ps, respectively. The current pulse amplitude of the second electron beam is higher than that of the first one, but the electron energy is less.

Key words: diffuse discharge, runaway electrons, streamer breakdown, displacement current