A tutorial overview of the angular scattering models of electron–neutral, ion–neutral, neutral–neutral, and Coulomb collisions in Monte Carlo collision modeling on low-temperature plasma

Over the past decade, extensive modeling practices on low-temperature plasmas have revealed that input data such as microscopic scattering cross-sections are crucial to output macroscopic phenomena. In Monte Carlo collision (MCC) modeling of natural and laboratory plasma, the angular scattering model is a non-trivial topic. Conforming to the pedagogical purpose of this overview, the classical and quantum theories of binary scattering, such as the commonly used Born–Bethe approximation, are first introduced. Adequate angular scattering models, which MCC simulation can handle as input, are derived based on the above theories for electron–neutral, ion–neutral, neutral–neutral, and Coulomb collisions. This tutorial does not aim to provide accurate cross-sectional data by modern approaches in quantum theory, but rather to introduce analytical angular scattering models from classical, semi-empirical, and first-order perturbation theory. The reviewed models are expected to be readily incorporated into the MCC codes, in which the scattering angle is randomly sampled through analytical inversion instead of the numerical accept–reject method. These simplified approaches are very attractive, and demonstrate in many cases the ability to achieve a striking agreement with experiments. Energy partition models on electron–neutral ionization are also discussed with insight from the binary-encounter Bethe theory. This overview is written in a tutorial style in order to serve as a guide for novices in this field, and at the same time as a comprehensive reference for practitioners of MCC modeling on plasma.