Comparative analysis of plasma-chemical models for computer simulation of glow discharges in air mixtures

Abstract

Subject of Research. We present research results for numerical modeling possibility of discharges in gas mixtures within the modern model of nonlocal plasma by creation a sequence of plasma-chemical and numerical models and comparing the results with experimental data. Method. Creation method for series of models with gradually increasing complexity has been used. It is based on a step by step expansion of the range accounted for elementary processes in nonlocal glow discharge plasma in the air. The air is approximated by the mixture of nitrogen and oxygen at low pressures under conditions suitable for experimental verification. For each iteration of plasma chemical scheme, corresponding numerical models of gas-discharge were created. The graphs of the discharge gap electrical parameters on the pressure were obtained by this method. Theoretical data obtained at each step have been compared to the experimental data and the results of previous computer models. Main Results. The model has been created that provides a good agreement with the experimentally obtained dependencies of the voltage drop across the discharge gap on the gas pressure in the areas of normal and abnormal glow discharge. By the updated model the optimum value for the coefficient of secondary electron emission from the cathode was chosen. Additionally, we have obtained the spatial distribution of the internal parameters of nonlocal plasma (longitudinal and transverse profiles of the electric potential, electron and ion densities, the electron temperature) as a subject to further experimental verification. Practical Relevance. The created models are perspective to be used for diagnosis and the setting of parameters of micro-discharges in the air. They have different applications, including developing method of electronic collision spectroscopy (CES) gas mixtures.