Momentum transfer collision frequencies between electrons and neutrals of astrophysical interest

Theoretical calculations serve as an effective method for determining plasma temperatures within planetary atmospheres. To simulate plasma temperature, a comprehensive implementation of the energy equation is used, which is governed by five terms: conductivity, heating, cooling, adiabatic expansion, and advection. The derivations mentioned are strongly dependent on the collision cross section between electrons and other particles (e.g., neutrals, ions). It is notable that the momentum transfer cross sections between electrons and neutrals have been updated in recent decades. However, the widely used momentum average collision cross sections between electrons and neutrals, derived from the momentum transfer cross sections, are collected in studies dating back nearly half a century. Therefore, it becomes imperative to revise the momentum average collision cross sections relevant to astrophysical contexts, based on the latest studies. In this study, we summarize the momentum average collision cross sections of 13 species common in planetary atmospheres: H, H₂, He, O, CH₄, H₂O, CO, N₂, O₂, Ar, CO₂, N₂O, and NO₂. All results are derived from the latest studies concerning the electron–neutral collision cross section and are compared with previous studies. Furthermore, we present a comparison of the derived total electron–neutral collision frequency at Mars between this study and previous studies. Prominent differences in the total electron–neutral collision frequency between this and prior studies support the significance of updating the momentum average collision cross section between electrons and neutrals in studying the planetary atmospheres.