Electron capture, loss and de-excitation in collisions involving fast metastable He+(2s) ions

Abstract

Cross sections sigma _1*0 for one-electron capture by ³He⁺(2s) ions in H₂, He, N₂, O₂, Ar and Kr have been measured in the energy range 15-55 keV, and compared with the corresponding cross sections sigma ₁₀ for one-electron capture by ground state He⁺ ions. Previously measured cross sections sigma _1*2 for electron loss by He⁺(2s) ions have been renormalized and both electron loss and electron capture are shown to be of comparable importance in the energy range considered. Destruction of He⁺(2s) ions is also shown to take place to a significant extent by collisional de-excitation processes.