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 Å2) 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 Å2; 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.