Influence of gas pressure and gas type on pseudospark electron beam

Abstract

Abstract Pseudospark discharge is a discharge that occurs in the left band of the Paschen curve. According to previous studies, an electron beam will be generated in the initial stage of pseudospark discharge. This electron beam has the advantages of high energy, high current and self-confinement. It has a promising application in high-power microwave sources, surface treatment of metal materials, etc. To investigate the characteristics of this electron beam, a pseudospark discharge experimental platform is established in this paper. A pseudospark chamber is designed for pseudospark discharge. To trigger the discharge, a high voltage pulse trigger signal is generated by an avalanche transistor Marx circuit and a trigger unit is designed to generate trigger electrons. Faraday Cup is utilized to collect the electron beam and measure the electron waveform. In order to quantitatively characterize the electron beam, we define six electron beam characteristics, including trigger delay, peak current, electron beam charge, electron beam width, electron beam loop current ratio and electron beam loop charge ratio. To investigate the influence of gas pressure and gas type on electron beam characteristics, we experimentally obtained results of electron beam characteristics for different gas pressures and gas type. We mainly investigated the change rule of the electron beam characteristics when the gas pressure changes between 6 Pa and 20 Pa and the similarities and differences of the electron beams under the two gas environments, argon and nitrogen. We find that gas pressure can be used for the modulation of electron beam time delay. The width of the electron beam in the case of nitrogen has a very stable relationship with the gas pressure. Gas pressure and gas type are two important means of controlling the characteristics of pseudospark electron beams.