Characteristics of Pseudospark Discharge in Particle-in-Cell Simulations

Abstract

In this paper, the characteristics of the pseudospark (PS) discharge were studied through particle-in-cell simulations with the consideration of the external circuit. The different discharge stages, including the Townsend discharge, hollowcathode discharge and super-dense glow, were characterized by the discharge voltage and current. The sources of electrons at different discharge stages were analyzed, with the electrons generated from the ionization of the background gas playing the dominant role. The electron densities at the Townsend discharge, hollow-cathode discharge and super-dense glow discharge stages were in the range of 10 13 m -3 , 10 18 m -3 and 10 20 m -3 , respectively. The energy of the electron beam extracted at the anode aperture at the different discharge phases was exported and post-processed. The electron beams generated at the three stages have an energy spread of 10%, 20% and 40%, respectively. The hollow-cathode discharge phase has balanced parameters in beam energy, energy spread, and electron density in contrast to the Townsend discharge and super-dense glow discharge stage.

Simulations of the Self-Focused Pseudospark-Sourced Electron Beam in a Background Ion Channel

“…The plasma density during the PS discharge process changes dynamically at different stages, from 10 13 -10 14 m -3 at the Townsend discharge stage, 10 16 -10 18 m -3 at the hollowcathode discharge stage, to 10 20 m -3 at the super-dense glow discharge stage [21]. The beam transportation at different ion densities in the hollow-cathode discharge stage was also simulated and the results are shown in Fig.…”

“…2. The PS discharge process was not included due to the large volume of the discharge cavity compared with the drift tube, which will significantly increase the computing time [21]. The simulation was carried out in cylindrical coordinates using XOOPIC [22].…”

Simulation of pseudospark discharge and the transportation of the generated electron beam

“…2 shows the densities of the electron and ion during the discharge process. It indicates the source of the electrons from the ionization of the background gas, and the secondary electrons have only a small contribution [9].…”

Characteristics of Pseudospark-Sourced Beam and its Application in THZ Sources

“…The schematic drawing of the discharge cavity used in the simulations is shown in Fig. 1, the simulations show different beam qualities are achieved at the different discharge stages [12]. The Townsend discharge (pre-breakdown) stage has the largest beam energy, which is close to the charging voltage at the anode.…”