<title>Simulation of electron transport in liquids under high electric fields</title>

Abstract

High Power Impulse (HPI) generation depends strongly on both the voltage and the rate of voltage rise which is applied to the radiating structure. Thus, placing the peaking switch at the apex of the antenna optimizes the transient radiating system. Liquids are prime candidates for the peaking switch media because of their high dielectric strength and its compatibility with lensing structures. The nature of the electrical breakdown initiation mechanism in liquids is not well understood. Electron processes are confirmed mechanisms of electrical breakdown initiation in gases, and it is natural to seek similar mechanisms for breakdown in the liquid state. The liquid state, however, contains many more scattering centers per unit volume, than in the gaseous state. An electron traveling through a liquid, then, undergoes many more collisions, most of which are inelastic. The electron, then, should quickly lose its energy to the background. Experiments have shown that, contrary to this intuitive conclusion, the electron transport coefficients tend to saturate under very high field conditions. A Monte Carlo simulation technique has been developed to investigate electron transport in liquids under high electric field conditions. This code adapts a computational technique that has been successfully used in electron kinetics of dilute gases by modifying the collisional crossection to accommodate the multiple scattering which occurs in the liquid.