The Influence of H–p, H–H Elastic Collisions, and Charge Transfer with Angular Scattering on the H Atom Velocity Distribution Function in a Plasma Layer

Fluid Dynamics. 2024. Vol. 59. No. 8. P. 2435–2444.

A. V. Titova, V. V. Izmodenov

In this study, we examine the influence of hydrogen–proton (H–p) and hydrogen–hydrogen (H–H) elastic collisions, along with charge transfer with angular scattering, on the velocity redistribution of hydrogen atoms within a plasma layer. To achieve this, we developed a kinetic model to explore H atom behavior in a homogeneous plasma region, assessing how these effects influence the maxwellization of the H atom distribution function relative to the case where only charge exchange is considered. The homogeneous layer results provide a simplified but valuable demonstration of how elastic collisions impact H atom behavior, creating a foundation for future studies in more complex, spatially varying plasma environments. Calculations of the distribution functions at various distances reveal that combined H–p and H–H collisions lead to faster maxwellization and blur the distinction between hydrogen atoms that have undergone charge exchange and those that have not interacted with protons.

Keywords: interstellar atoms, charge transfer, heliosheath, elastic collisions