Anisotropic angular scattering models of elastic electron-neutral collisions for Monte Carlo plasma simulation

Many laboratory and industrial plasma applications require accurate modeling techniques to understand the interplay between microscopic and macroscopic processes. A prime example of this interplay is how particle and Monte Carlo simulation codes use angular scattering of electrons following elastic scattering events in order to help simulate plasma devices. The forward peaked nature of high energy electron elastic scattering is relatively trivial to accurately describe in plasma simulations. However, for lower energy collisions, which produce near isotropic or backward peaked differential cross sections, there is not a strong consensus among the plasma modeling community on how to best describe these angular scattering trends. In this study, we propose a systematic method to approximate the aforementioned non-trivial angular scattering behavior with a formula that can be readily implemented in Particle-in-Cell and/or Monte Carlo plasma simulation codes. Specific application of this method is demonstrated for fusion relevant atomic hydrogen and helium, as well as for molecular hydrogen.