A regularized high-order moment model to capture non-Maxwellian electron energy distribution function effects in partially ionized plasmas

A model for electrons in partially ionized plasmas that self-consistently captures non-Maxwellian electron energy distribution function (EEDF) effects is presented. The based on the solution of scalar and vectorial velocity moments up to contracted fourth-order moment. set fluid (macroscopic) equations obtained with Grad's method exact expressions collision production terms are derived, considering electron–electron, electron–gas, electron–ion elastic collisions as well electron–gas excitation ionization collisions. regularization proposed order avoid spurious discontinuities, existing original moment model, by using a generalized Chapman–Enskog expansion exploits disparity mass between heavy particles (ions atoms) plasma gas densities, typical discharges. transport includes non-local due spatial gradients EEDF impact calculation inelastic rates. Solutions under spatially homogeneous conditions compared direct simulation Monte Carlo two-term Boltzmann solver representative high density discharges at low-pressure. able capture evolution EEDF, good quantitative agreement kinetic solutions. coefficients rates an argon thermal non-equilibrium effect electric field solutions solver, largely improving models simplified Bhatnagar–Gross–Krook collisional operator.