An optimized collision-averaged variable soft sphere parameter set for air, carbon, and corresponding ionized species

Abstract

A collision-averaged parameter set for air, carbon, and the corresponding ionized species for the variable soft sphere collision model is suggested which is suitable for the earth's atmosphere or mars atmosphere, for example. The parameter set is generated through collision integral fits and a number of optimization steps so that individual sub-sets can also be used for, e.g., air or without ionized species. In addition, the parameter set can be extended by further species without having to carry out the complete optimization again, which is shown in the example of argon. The limitations of the collision-average model are discussed and in which cases the collision-specific model or other models should be used. The model is compared with collision integrals from various publications.