Electron capture by doubly charged ions from laser-excited alkali atoms: I. He²⁺-Na*(3p) collisions

Abstract

State-selective single electron capture in slow (0.5-3 keV amu -1 ) collisions of He 2+ with laser-excited Na*(3p) atoms has been studied by means of translational energy spectroscopy and the results compared with 64-state atomic orbital (AO) close coupling calculations, considering cross sections for electron capture into He + (n=3,4,5) final states for different impact energies. In addition, alignment effects have been studied by controlling the polarization of the exciting laser light. The experimentally observed dependence on Na*(3p Sigma ) and Na*(3P Pi ) initial state preparation is quantitatively reproduced by the AO calculations.