Inelastic energy losses in collisions of 40–90 keV Ar + ions with solid and gaseous Cu targets

Abstract

Large-angle scattering of 40, 60 and 90 keV Ar + ions against Cu atoms is studied. Both free atoms and atoms situated at the surface of a solid are used as target atoms. The inelastic energy losses are derived from the scattering angles and the kinetic energies of the scattered ions. The inelastic losses initially increase with increasing center-of-mass scattering angle and reach plateau values of about 850, 1100, and 1300 eV for primary energies of 40, 60, and 90 keV, respectively. It is found that the physical state of the target has no noticeable influence on the result of these measurements. The inelastic energy losses measured at a given primary energy and scattering angle show a distribution around an average value. The half-width of this distribution is found to be in the order of 50% of the average inelastic energy loss, independent of the kinetic energy of the incoming ion.