ELECTRON REMOVAL FROM ATOMIC-HYDROGEN BY COLLISIONS WITH FULLY STRIPPED OXYGEN IONS

Cross sections for charge transfer and impact ionization in O8+ + H collisions have been calculated in the range of collision velocities (0.1-10) × 108 cm/sec. At the lower velocities, up to 1.2 × 108 cm/sec, charge-transfer cross sections were determined by means of the perturbed-stationary-state method in the impact-parameter approximation with a selective basis set of adiabatic one-electron two-center orbitals. The charge-transfer cross section increases monotonically in this region, attaining a value of 8 × 10-15 cm2 at 1.2 × 108 cm/sec. Rotational coupling was found to be an important mechanism which contributes significantly to the large cross sections in the molecular regime. Thus the present results are at least a factor of 2 larger than previous Landau-Zener calculations. Above 2.2 × 108 cm/sec, a classical-trajectory Monte Carlo approach was used to compute both charge-transfer and ionization cross sections. At velocities above 5 × 108 cm/sec, ionization becomes the dominant electron-removal process. © 1979 The American Physical Society.