Inelastic collisions of 2--800-eV He+ and He2+ with Mg and Zn atoms

Inelastic processes leading to excited-state formation have been studied by spectral analysis of collision-produced uv--visible-near-ir radiation for (2--800 eV) He+ and He2/sup ts+/ collisions with Mg and Zn atoms. Although observation of Mg II radiation must result from exothermic charge transfer in the He+-Mg system, the emission cross sections for the two observed Mg II lines exhibit threshold behavior; it is suggested that production of ground-state Mg III dominates at low energy. He2/sup ts+/-Mg collisions yield two prominent Mg II lines, the emission cross sections for which are relatively large at low energy and decrease rapidly with increasing kinetic energy. He+-Zn collisions produce rich spectra of Zn II lines at all energies and He I lines at elevated energies. In contrast, He2/sup ts+/-Zn collisions yield only a few lines with large cross sections at low energy