Charge-transfer and impact-ionization cross sections for fully and partially stripped positive ions colliding with atomic hydrogen

Classical trajectory calculations have been used to predict the charge-transfer and impact-ionization cross sections for collisions of A+/sup q/ + H in the velocity range of (2--7) x 108 cm/sec. The calculations employ a three-dimensional Monte Carlo approach that uses a classical description of the H atom and the Coulomb forces among all particles to obtain the cross sections. The positive ions studied include fully stripped A+/sup q/, with q = 1--8, 10, 14, 18, 26, and 36, and partially stripped B+/sup q/, C+/sup q/, N+/sup q/, and O+/sup q/, with q > or = 3. The total electron-loss cross sections (sum of charge exchange and impact ionization) vary only slightly with velocity for the higher charge states and reach a value of 2 x 10-14 cm2 for Kr+36 + H collisions. The importance of impact ionization relative to charge transfer is found to decrease with increasing q in the velocity range studied. Transition probabilities versus impact parameters are presented for the H+ + H and Ar+18 + H reactions. The calculations are in reasonable agreement with experimentally measured cross sections for the H+, C+/sup q/, N+/sup q/, and O+/sup q/ + H systems