Symmetric charge transfer in low-energy ion-atom collisions

Previous calculations of ion-atom interactions by the pseudopotential and asymptotic methods are used in the computation of the cross section for symmetric charge transfer at energies below 1 keV. The results for Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺, and Ca⁺ ions are compared with data obtained in beam experiments, and by optical-pumping techniques. The difference in the cross sections for ²P1/2 and ²P3/2 ions of Kr⁺ and Xe⁺ at thermal energies is studied, and the predictions are compared with recent mobility measurements. Cross sections are obtained for U⁺-U collisions, and the dependence of the thermal cross section on the polarizability is described. Symmetric charge transfer of the negative ions H^-, Na^-, and Cs^- is discussed briefly.