Zero-Dimensional Theoretical Model of Subnanosecond High-Pressure Gas Discharge

This paper deals with the results of the breakdown process simulation in strongly overvoltage gaps under high pressures. The presented 0-D model of discharge enables the estimation of characteristic parameters of the initial stage of the breakdown: current rise rate, time of voltage decay across the gap, and current pulse duration of runaway electrons. The discharge model takes into account 0-D growth kinetics of the plasma density in the gap and the impact of the external power supply circuit of the discharge, including the interelectrode capacitance. The model enables estimation of the number and energy range of runaway electrons generated at the initial stage of high-pressure gas breakdown. As an example, computations were conducted for discharge in nitrogen. A comparison of the simulation results with the experimental data enables estimation of the level of the critical field in which we can expect the generation of runaway electrons in the gas discharge.