Production of orientation and alignment in heavy-ion-surface collisions

Abstract

We have measured the alignment and orientation parameters of forward-scattered argon ions excited in grazing-incidence collisions with a Cu surface. The polarization of the light emitted from excited scattered ions has been measured simultaneously with a measurement of their spatial position relative to the interaction region. We have measured the dependence of the orientation with ion energy, incidence angle, scattering angle, and surface material. Total ion angular distributions are found to be independent of incident energies between 0.50 and 3.0 MeV. Possible excitation mechanisms for producing the observed charge states, excited states, alignment, and orientation are discussed. We compare this surface excitation with the excitation of ions passing through thin foils.