DIRECT MEASUREMENT OF THE ENERGY-RELEASE AND FINAL MOLECULAR AXIS ORIENTATION IN DISSOCIATIVE MOLECULAR-SCATTERING AT SURFACES

We describe a technique for the direct measurement of the kinetic energy release and final molecular axis orientation in dissociative molecular scattering at surfaces. The energy released and the final orientation are derived in principle from coincident measurement of the laboratory-frame velocities of the dissociation fragments. The measurement principle is independent of either the charge state, translational or internal energy of the incident beam, and can be used to investigate dissociative scattering of both homonuclear and heteronuclear molecules. To illustrate the technique we present some results of an investigation of the dissociative scattering of H-2+ and H-2 from a Cu(111) surface under glancing incidence conditions.