Townsend's Secondary Ionization Coefficient of MgO Film in Ar and Electron Reflection at the Surface

Abstract

Previously, a Monte Carlo simulation (MCS) was carried out to determine the Townsend's secondary ionization coefficient γ of a MgO film using the experimental values of starting voltage between the electrodes covered by the MgO film. The electrodes were mounted at the center of a chamber as a modeled plasma display panel (PDP) cell filled with Ar. The purpose of the study was to examine the effect of the energy in a nonequilibrium state of electrons on the Townsend's secondary ionization coefficient. It was confirmed that the energy nonequilibrium effect appeared and the effect strongly depended on the initial energy distribution of electrons emitted from the cathode. The values of γ considered in the nonequilibrium of electron energy were approximately 20% larger than those considered in energy equilibrium under the operating conditions of the PDP. In this study, we investigated the effect of electron reflection on both electrode surfaces on the secondary ionization coefficient and the electron transmission coefficient. The electric power injection into the gap space based on the electron transmission coefficient and the dynamic characteristics of electron flux at the anode are explained using the electron reflection coefficient obtained in our previous experiments.