High-energy cross sections forH−ions incident on intermediate and high-Zatoms

The double-closure Born approximation developed in previous work is used to calculate the asymptotic cross sections for electron loss from ${\mathrm{H}}^{-}$ ions incident on a variety of atomic targets. Corrections to the closure technique for the next-order terms in heavy-ion-atom cross sections are examined. The corrections for energy conservation are shown to be unimportant, but the Bethe ridge in the inelastic form factors does yield terms which contribute to the next leading order. The total asymptotic electron-loss cross section, and the next-order contribution including the Bethe ridge correction, are calculated using various models for the target atoms obtained from the literature. Comparative results based on Hartree-Fock, configuration-interaction, and relativistic Hartee-Fock wave functions are presented. The results for the electron-loss cross sections for N, O, and Ar target atoms are compared with the available experimental data. Results are also given for parameters which are required for the asymptotic elastic and nondetachment inelastic cross sections. Some comments regarding other applications of these methods are included.