Differential measurements of ionization and inelastic energy losses in 0.25—3.0-MeV collisions of Kr ions with Kr and Xe targets

Abstract

The final charge states of the scattered ions and the inelastic energy losses have been measured for single collisions of 0.25---3.0-MeV Kr ions with Kr and Xe targets. The charge states of the scattered ions were measured as functions of scattering angle (from 0.8\ifmmode^\circ\else\textdegree\fi{} to 45\ifmmode^\circ\else\textdegree\fi{}) ion energies from 0.25 to 3.0 MeV. The total inelastic energy losses were measured using the scattered- and recoil-particle coincidence technique for 0.4-, 0.6-, and 1.0-MeV ${\mathrm{Kr}}^{+}$-Kr collision energies and from 0.4 to 1.4 MeV for the ${\mathrm{Kr}}^{+}$-Xe combination. The results show the impact-parameter dependence of several inner-shell excitations and confirm the quasimolecular nature of heavy-ion---atom collisions within the framework of the Fano-Lichten model. For the Kr-Kr case, excitations are observed for values of the distance of closest approach, ${R}_{0}$, of 0.40, 0.30, and 0.20 \AA{}; and for the Kr-Xe case, excitations are observed at ${R}_{0}$ values of 0.28, 0.18, and 0.09 \AA{}. The data show agreement with the molecular-potential calculations of Eichler and co-workers.