Velocity and angular distributions for Xe scattered from clean Pt(111) have been observed which permit the scattering process to be experimentally divided into a direct inelastic channel and a trapping-desorption channel. The trapping-desorption channel leads to Maxwellian velocity distributions at the surface temperature and a $cos\theta$ angular dependence, while the direct inelastic channel exhibits a linear relationship between exit kinetic energy and both incident kinetic energy and surface temperature.

• Received 4 May 1979

DOI:https://doi.org/10.1103/PhysRevLett.43.1175