Analytic cross sections for inelastic collisions of protons and hydrogen atoms with atomic and molecular gases

Abstract

Analytic formulas are given for inelastic cross sections for collisions of protons and hydrogen atoms with atomic and molecular gases in the energy range 0.5 kev to 5 Mev. They are convenient interpolation formulas that span the broad energy region important in atmospheric physics, astrophysics, radiation physics, and plasma physics. The asymptotic form of the analytic expressions is shown to be equivalent in appropriate cases to theoretical results obtained with the well-known Born approximation. The parameters of the formulas are evaluated for noble gases and for diatomic atmospheric gases with the aid of electron impact data and recent results of proton and hydrogen atom impact experiments. The systematics of the parameters are discussed.