Numerical analysis of plasma properties in the glow discharge: accuracy and applicability of simple and extended fluid models

Kaymazlar, Koray
The work deals with numerical investigation of physical processes in the gas discharge plasma. Numerical models are based on the fluid description of plasma, with drift-diffusion approximation for charged particle fluxes. First, we developed a “simple” fluid model, consisted of continuity equations for electrons and ions, coupled to Poisson equation for electric field. Next, we extended this model by incorporating the electron Boltzmann equation module, such that the electron transport parameters (mobility and diffusion) as well as the rates of electron induced plasma-chemical reactions are determined as functions of the local electric field, from convolution of the electron energy distribution function. The numerical method is based on the Method of Lines, where discretization in the coordinate space (as well as in the energy space for Boltzmann equation) is done by the Scharfetter-Gummel scheme. All numerical codes are developed using MATLAB package. Computational tests are carried out for glow discharge plasma in argon. Comparison of computed plasma parameters (such as the electron and ion densities, the electric field and potential, the current-voltage curves) obtained by “simple” and “extended” fluid models with one another and with experimental data allow to determine the accuracy and the ranges of applicability of these models.