Ejected electron spectra from doubly-excited states (2lnl') of He-like ions produced by the B5+, C6+-He collisions

Ejected electron spectra from the doubly-excited helium-like ions produced by the double electron capture collisions of bare ions B5+ and C6+ with He have been measured using zero-degree Auger electron spectroscopy with a high energy resolution. Electrons from the configuration of (2lnl') have been observed for n ≥ 2 in B5+ -He collisions and N ≥ 3 in C6+ -He collisions. Experimental energy values of ejected electrons from the (2l2l') and (2l3l') states of B3+ ions and the (2l3l') states of C4+ ions are determined by comparing the observed spectra with the theoretical calculations. Spectral features have also been observed at different collision energies. The population mechanisms to those states are briefly discussed. (author)