Production of Long-Lived H[sub 2][sup −], HD[sup −], and D[sub 2][sup −] during Grazing Scattering Collisions of H[sub 2][sup +], H[sub 3][sup +], D[sub 2][sup +], D[sub 3][sup +] and D[sub 2]H[sup +] Ions with KBr, KCl, and LiF Surfaces

Abstract

We have investigated atomic and molecular anion production from singly charged atomic and molecular hydrogen, deuterium, and mixed isotope beams during grazing interactions with large area KBr, KCl, and LiF single crystal targets in the incident energy range 4–22.5 keV. Electron capture and, in the case of incident molecular ions, dissociation occur during the grazing interactions without appreciable angular straggling or change in velocity. As a result, atomic and molecular cation and anion interaction products are strongly peaked in the specular reflection direction, and, in case of dissociation products, at the fractional kinetic energies determined by the product fragment mass to incident mass ratios. A large‐acceptance electrostatic analysis and detection system is used to collect the charged scattering products with high efficiency. Of particular interest is the production of metastable molecular ions H2−, HD−, and D2−. By comparing molecular anion yields obtained from incident hydrogen, deuterium a...