Low-energy charge transfer in collisions of He2+with H in a Debye plasma

Abstract

Charge transfer in collisions of $\ensuremath{\alpha}$ particles with ground-state H embedded in a Debye plasma is studied in the low-energy region from $10$${}^{\ensuremath{-}4}$ eV to $5$ keV. The screened Coulomb interaction is described by the Debye-H\"uckel potential. The relevant molecular potentials and coupling matrix elements are obtained using a modified multireference single-and double-excitation configuration interaction package. Total and state-selective cross sections in the nonradiative charge-transfer collisions from $60$ eV to $5$ keV are calculated using the quantum-mechanical molecular-orbital close-coupling method. Both optical-potential and semiclassical methods have been used in the investigation of the radiative charge transfer from $10$${}^{\ensuremath{-}4}$ to $1$ eV and $1$ to $10$${}^{2}$ eV, respectively. The total cross sections for the no-screening case are in good agreement with the existing data. The effects of the screened Coulomb potential on the electron-capture cross sections are discussed.