State-selective double capture in collisions of bare ions with helium atoms at low energies. II. Ejected-electron spectra

For pt.I, see ibid., vol.24, no.19, p.4215 (1991). The Auger electron spectra of double excited states of ions resulting from double capture in collisions of bare ions with helium atoms in the energy range of a few keV amu -1 are calculated. The electron capture amplitudes are obtained in the independent-electron approximation. By combining these amplitudes with the Auger decay amplitudes and taking into account the post-collision interaction effect and the interference from different states, the electron spectra as a function of the ejection angles are evaluated. Calculations have been carried out for the electron spectra of 2l3l' doubly excited states of C 4+ from C 6+ -He collisions and of 3l3l' double excited states of O 6+ from O 8+ -He collisions. The theoretical results are compared with measured Auger electron spectra.