Charge exchange in He++Li collisions

A two-state model, based on atomic wave functions and allowing for momentum transfer factors, is employed to calculate cross sections for the formation of excited states of He⁺ in collisions of He⁺⁺ ions with Li in the ground state, for energies in the range 5–64 keV. It is shown that the selective capture into the n=3 levels of He⁺, predicted at low energies by Shipsey et al., persists up to energies of ≈30 keV.