Kinetic Simulations of Hollow Cathode Discharge and Its Interactions With Different Target Materials

The electron beams in pseudospark discharges ignited in hollow cathode discharges play an important role in material processing. In this study, we investigated the characteristics of electron beams generated by pseudospark discharge in the presence of a target material using fully kinetic 2-D particle-in-cell/Monte Carlo collision (PIC/MCC) (2-D in space and 3-D in velocity, 2d3v) simulations. The properties of the targets were analyzed based on charge accumulation and secondary electron yield (SEY) coefficient properties to investigate their effects on the discharges and electron beams. The plasma density evolution, formation of a virtual anode, and pendulum electrons were examined to demonstrate the pseudospark discharge characteristics in the presence of the target materials. Furthermore, we examined the effects of different target properties on the electron beam through the electron current and electron energy distribution functions (EEDFs) as well as by accounting for variations in the working pressures and target distances. The results clarify the effects of target materials on electron beam and pseudospark discharge, providing fundamental insights applicable to both discharge physics and practical applications in material processing.