A study of charge transfer and excitation processes in collisions of alpha particles with sodium atoms

Abstract

The coupled state impact parameter model has been used to study collisions of alpha particles with sodium atoms. Straight-line trajectories are employed. The charge exchange and excitation cross sections are computed for impact energies in the range 10.0-270.0 keV. The calculated total charge exchange cross sections are found to be in good agreement with the recent experimental data of Dubois and Toburen (1985) in the energy range 10.0<or=Elab<or=100.0 keV. It is predicted that above this energy electron capture from the L shell starts to compete with electron capture from the M shell which is considered. The authors find that, for impact energies below 30.0 keV, the electrons are preferentially captured in the He+ (3l) state. This leads to a distinct possibility of population inversion and emission of Lyman- alpha (304 AA) and Lyman- beta (256 AA) soft X-ray photons.