Dissociation of fast HeH+ ions at glancing angle scattering from a crystal surface

Abstract Scattered H + fragments resulting from glancing angle incidence of MeV HeH + ions on the clean (001) surface of a SnTe crystal are distributed on an ellipse in the E - φ plane, where the angle φ is measured in the plane parallel to the surface and E is the energy of the fragment. The kinetic energies released upon dissociation derived from the diameters of the ellipses are smaller than those calculated from the explosion of fully ionized fragments. Based on a simplified model, we have simulated the dissociative scattering of HeH + ions at the surface, where the dissociation takes place via excitation of HeH + ions and the charges of fragments change along the trajectory. It is concluded from the simulation that the cross section for dissociation in HeH + -electron collisions is of the order of 10 −16 cm 2 .