title: Electronic excitations of slow ions in a free electron gas metal: evidence for charge exchange effects.
abstract: Electronic energy loss of light ions transmitted through nanometer films of Al has been studied at very low ion velocities. For hydrogen, the electronic stopping power S is found to be perfectly proportional to velocity, as expected for a free electron gas. For He, the same is anticipated, but S shows a transition between two distinct regimes, in both of which S is velocity proportional-however, with remarkably different slopes. This finding can be explained as a consequence of charge exchange in close encounters between He and Al atoms, which represents an additional energy loss channel.
authors: Institut für Experimentalphysik, Johannes-Kepler Universität Linz, Linz, Austria.
authors: D
authors: D
authors: Primetzhofer
authors: S
authors: S
authors: Rund
authors: D
authors: D
authors: Roth
authors: D
authors: D
authors: Goebl
authors: P
authors: P
authors: Bauer