Reactions of diatomic rare-gas ions with rare-gas atoms for primary-ion energies below 50 eV

Abstract

Reactions of He⁺₂, Ne⁺₂, and Ar⁺₂ with rare‐gas atoms have been studied for center‐of‐mass energies, E₀, below 40 eV. Electron transfer, collision‐induced dissociation of the primary ion, and ion transfer have all been observed. At E₀=1 eV, electron transfer sometimes occurs with very large (∼50 Ų) cross sections; however, sometimes the cross section for electron transfer is small. The observed cross sections for electron transfer increase as E₀ is decreased. Collision‐induced dissociation of the primary ion occurs with maximum cross sections of 1.5–25 Ų; these cross sections fall off as E₀ is lowered below some value. The cross sections for the collision‐induced dissociation of He⁺₂ are observed to be smaller than the cross sections for the collision‐induced dissociation of Ne⁺₂ and Ar⁺₂. Ion transfer is observed in only two cases: Ar⁺₂+Ne → ArNe⁺+Ar and Ne⁺₂+He → NeHe⁺+Ne; the cross sections for these reactions increase as E₀ is lowered.