Modelling of low-pressure gas breakdown in uniform DC electric field by PIC technique with realistic secondary electron emission

This paper compares the basic phenomenological model based on the Townsend's theory and the detailed simulation of the gas breakdown in argon in uniform DC electric field. Calculations were carried out by using a one-dimensional particle-in-cell/Monte Carlo (PIC/MCC) code with three velocity components with a new secondary emission model. The simulation results clearly show how different models of the secondary electron emission affect the breakdown voltage. The fact that results of simulation are in a good agreement with the available experimental data merely means that phenomenological secondary electron yields were developed to fit the experiment. However, oversimplified models cannot predict all features of Townsend discharges and cannot be reconciled with binary collision data. One such example is the need to predict the DC volt-ampere characteristics in order to reveal the predominant physical processes by studying the j/p(2) scaling.