Stopping of swift hydrogen diclusters: oscillator model
Department of Physics and Chemistry, University of Southern Denmark, 5230 Odense M, Denmark
2 Institut für Experimentalphysik, Johannes Kepler Universität, 4040 Linz-Auhof, Austria
Corresponding author: a firstname.lastname@example.org
Revised: 31 August 2010
Published online: 3 December 2010
Enhanced stopping of swift hydrogen diclusters has been analysed theoretically. The target has been modeled as a gas of harmonic-oscillator atoms of variable density. This model predicts a proximity effect, i.e., enhanced stopping at high beam energy, and an oscillatory behavior at low energy. Both features get less pronounced with increasing target density due to increased screening of the ion-target interaction by polarization of the medium. Static screening by electrons accompanying the cluster likewise reduces the proximity effect. The Barkas-Andersen correction has been estimated in the limit. Our findings are in contrast with measurements on SiO2 [S.M. Shubeita et al., Phys. Rev. B 77, 115327 (2008)] which showed a pronounced step in the energy dependence of the proximity effect.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2010