Improving PIC-DSMC Simulations of Electrical Breakdown via Event Splitting

Abstract

A newly developed variable-weight DSMC collision scheme for inelastic collision events is applied to PIC-DSMC modelling of electrical breakdown in 1-dimensional helium and argon-filled gaps. Application of the collision scheme to various inelastic collisional and gas-surface interaction processes (electron-impact ionization, electronic excitation, secondary electron emission) is considered. The collision scheme is shown to improve the level of noise in the computed current density compared to the commonly used approach of sampling a single process, whilst maintaining a comparable level of computational cost and providing less variance in the average number of particles per cell.

Improving PIC-DSMC Simulations of RF Plasmas via Event Splitting.

“…Another approach to improvement of modelling of low-probability processes was recently proposed, 19,20 dubbed "event splitting", in which the variable-weight particles are split proportionally to the probabilities of processes that can take place during a given collision. It was shown that use of event splitting for collisions and boundary conditions with secondary emission can noticeably reduce the noise in PIC-DSMC simulations compared to the use of standard sampling approaches to collision process modelling.…”