Radiative charge transfer in collisions ofHe2+ions and ground-state H atoms

Total cross sections for radiative charge transfer in collisions of ${}_{}{}^4{}_{}{}^{}\mathrm{He}_{}^{2+}{}_{}{}^{}$ ions with ground-state H atoms leading to ${\mathrm{He}}^{+}$ $1s$ and ${\mathrm{H}}^{+}$ ions have been calculated for a range of center-of-mass energies from 0.1 to 1000 eV. An adiabatic optical-potential formalism is used where the imaginary part of the potential-energy function is proportional to the Einstein $A$ coefficient for the molecular transition. Both quantum-mechanical and semiclassical JWKB calculations are performed. Predissociation resonances add structure to the cross section. The radiative contribution is shown to dominate the charge-transfer process for this system at low collision energies.