Simulation of the statistical and formative time delay of Townsend-mechanism-governed breakdown in argon at low pressure

Abstract

Understanding the breakdown process is important both from fundamental and practical perspectives. One of the most important quantities that characterize the breakdown is the breakdown time delay. In this article, numerical models for self-consistent simulation of the statistical and formative time delay of the electric breakdown in argon at low pressure have been proposed. The first model, based on the Monte Carlo simulation of the electron avalanche development, is used to simulate the statistical time delay. The model is designed for low-pressure breakdowns when the Townsend mechanism is dominant. The electric breakdown is then governed by ion-induced secondary electron emission from the cathode. In that case, the statistical time delay to breakdown is determined by tracking the waiting time of emission of the primary electron that initiates the electron avalanche and the number of ions produced in it. On the other hand, the formative time delay is determined by simulating the electric current waveform (Formula presented.) using the fluid model. To test whether the proposed models can be used for discharges operating under various conditions, the voltage dependence is simulated for both the statistical and the formative time delay. The results of the simulations show good agreement with the experimental results and theoretical models.