Charge-transfer processes in collisions ofH+ions with phosphorus atoms at low energies

Abstract

We have carried out a theoretical investigation of charge transfer in collisions of ${\mathrm{H}}^{+}$ ions with neutral phosphorus P atoms both in the ground and metastable states at collision energies below 10 keV/u and above 100 eV/u using a molecular representation. Molecular states for the ${\mathrm{PH}}^{+}$ molecule are obtained by employing the ab initio multireference (single- and double-excitation) configuration-interaction method. In calculating charge-transfer cross sections, we have adopted the semiclassical impact-parameter method. The present charge-transfer cross sections from the ground-state P target are found to reach as large as $2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}15}{\mathrm{cm}}^{2}$ at 1 keV/u after slowly increasing from lower energies, and the contribution from ${\mathrm{P}}^{+}{(}^{3}P)$ and ${\mathrm{P}}^{+}{(}^{5}{S}^{o})$ formations to the total are found to be comparable at the energy region where the cross section possesses a maximum.