Dissociative excitation and fragmentation cross section of HeH+ molecular ions in collision with He

Abstract

We investigated H+ and He+ fragment production from the dissociation of HeH+ ions in collision with a He target. This occurs through either the He++H or the He+H+ channel. We also investigated He2+ and H- production, which are three orders of magnitude smaller than those for H+ and He+. The He+/H channel seems to be favored over the H+/He channel at all acceleration energies as well as at all ion source pressures. The H+ and He+ cross sections appear to be independent of the acceleration energy while they show significant dependence on ion source pressures. The center of mass energy distribution for both H+ and He+ shows a kinetic energy release of near zero eV. Our results suggest that the initial state of the parent HeH+ molecular ions is that of a mixture of ground electronic state as well as metastable excited states with the a (3)Sigma(+) dominant.