State-to-state Scattering of Metastable CO Molecules from a LiF(100) Surface

Survival of electronically excited, state-selected CO(a³Π) molecules scattering from a cleaved LiF(100) surface is studied. Absolute survival probabilities are determined for various impact energies. Time-of-flight profiles, angular distributions, and internal state distributions of the surviving metastable CO molecules are measured. The dependence of their translational and rotational temperatures on the incoming velocity unambiguously indicates a direct inelastic scattering process even though the angular distributions are broad, both in plane and out of plane.