Excitation Kinetics of Oxygen O(1D) State in Low-Pressure Oxygen Plasma and the Effect of Electron Energy Distribution Function

Abstract

We develop numerical model to discuss the number density and excitation kinetics of O(1D) state in low-pressure discharge oxygen plasma. The governing equations are the Boltzmann equation to describe the electron energy distribution function and the rate equations of the relevant excited states. We have calculated them back and forth until self-consistent solution is obtained. When the rate coefficient of the electron impact dissociation of O2 to O(3P) and O(1D) atoms is assumed to be functions of electron temperature Te with Maxwellian electron energy distribution, the obtained results are found to be inappropriate. When the rate coefficients are written as functions of electron energy distribution function, satisfactory results are obtained as number density distribution of excited states. We also experimentally examined and confirmed the validity of the model by actinometry measurement for number density of the O(3P) state. It is found that we should consider the electron energy distribution function in describing the excitation kinetics of O(1D) state in low-pressure oxygen plasma.