A kinetic study of the local field approximation in simulations of AC plasma display panels

Abstract

Electron kinetics determine the rates at which a multitude of electron-driven processes will proceed in low-temperature, weakly ionized plasmas. Consequently, reliable simulations of such discharges often require Boltzmann-type kinetic simulations which can self-consistently describe the electron kinetics. Since kinetic simulations tend to be computationally intensive, fluid or hydrodynamic approximations are often imposed to provide faster and more practical alternatives to kinetic simulations. Fluid simulations, however, cannot self-consistently provide the electron-driven rates. Instead, one typically incorporates a local field approximation (LFA) which relies on the parametrization of the rates of some local, bulk property of the plasma such as the local E/N. Using self-consistent Boltzmann simulations of AC plasma display panel discharges, we have compared kinetically derived rates against those obtained parametrically from the LFA. The data were used to construct a space-dependent, kinetic correction (KC) curve for the LFA rates and then incorporated into self-consistent Poisson/fluid simulations. Additional simulations without the KC were also performed, and all results were compared to kinetic simulations. We found that the KC provides considerable improvement over the fluid simulation results. Furthermore, we found that the non-KC results could be reconciled with the kinetic and KC simulations by considering all potentials relative to the breakdown potential.