Electron Energy Deposition in a Gas Mixture of Atomic and Molecular Hydrogen and Helium

A detailed discussion is presented of the slowing down of fast electrons in a partly ionized gas mixture of H, H2, and He with a varying ratio of H to H2 and a fixed fraction of He. The mean energies and yields for ionization, electronic excitation, dissociation, and vibrational excitation and the heating efficiencies are calculated for fractional ionizations from 0 to 0.1. Analytical formulas are obtained for many of the parameters.