ROLE OF PROJECTILE-MOTION-INDUCED ELECTRONIC-TRANSITIONS IN THE DISSOCIATION OF FAST H-2 AT A CU(111) SURFACE

We report measurements of the final molecular axis orientation, released kinetic energy and incident beam translational energy dependence of dissociative scattering of 500-6000 eV H-2 and H-2+ from Cu(111) under glancing angles of incidence (normal energies 0.7-4 eV). We find some evidence that the scattering dynamics of those molecules initially in the ground X 1SIGMA(g)+ state may be influenced by the topography of the continuum manifold of PES correlating with the adiabatic ground state. However, we suggest that electronic transitions from the ground state manifold to a dissociative upper state manifold are ultimately responsible for the dissociative scattering events we detect.