Angular distribution of autoionization electrons and sublevel population in low energy He+-He collisions

Abstract
The recent theory of Cleff and Mehlhorn (1974) on the angular distribution of Auger electrons is applied to explain the angular distribution of electrons ejected by autoionization of the 2p1 1D state of helium, as observed in He+-He collisions at 15 keV. The unequal populations of the 1D magnetic sublevels are explained by a quasi-molecular excitation mechanism; the population of the sublevels mod ML mod =1 and ML=0 is ascribed to a rotational coupling at large internuclear distance.