Molecular-alignment dependence of collision-induced dissociation and electron capture in H_2~+ He collisions

摘要

The collision-induced dissociation (CID), electron capture (EC), and dissociative capture (DC) processes in H_2~+ He collision are investigated by the quantum-mechanical molecular-orbital close-coupling method in the energy range of 0.02-10 keV/u. The studies are based on the ab initio calculation of the molecular structure data for different H_2~+ alignments with respect to the incident beam direction. The cross sections are compared with the available experimental and theoretical results. The CID process dominates the EC and DC processes. The CID cross sections sensitively depend on the molecular orientations at the time of dissociation, in the energy region considered. Dissociation is found to be more likely to occur when the molecular axis is aligned perpendicular to the collision trajectory. The rotational couplings play an important role in dissociation processes.