title: Velocity scaling of ion neutralization in low energy ion scattering.
abstract: The ion fraction P+ is measured for He+ ions scattered by 129 degrees from a Cu surface. Both the primary energy and the angles of incidence and of exit are varied. From our results we conclude the following: along the incoming and outgoing trajectories, neutralization is due to Auger processes and depends on the normal velocity component v( perpendicular ) only. At higher energies, additional charge exchange is due to collision induced neutralization and reionization, both depending on the total ion energy only. Also in this regime P+ depends on v( perpendicular ), but via a two-valued function of the scattering geometry at fixed energy.
authors.affiliation: Institut fuer Experimentalphysik, Johannes Kepler Universitaet Linz, A-4040 Linz, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Draxler
authors.forename: R
authors.initials: R
authors.lastname: Gruber
authors.forename: H H
authors.initials: HH
authors.lastname: Brongersma
authors.forename: P
authors.initials: P
authors.lastname: Bauer