Quasi-elastic scattering of Neon from (001)LiF surface

In scattering measurements of atoms and molecules from surfaces the intensities of the diffraction and specular peaks contain contributions from quasi-elastic scattering events, in addition to the coherent elastic scattering. These may occur because of inelastic collisions with very small changes in energy and momentum and because of elastic collisions with random defects of the surface. In the present article it is shown how to separate the quasi-elastic contribution from the elastic one by measuring both angular and energy distributions of the scattered particles. As an example the procedure is used to study the scattering of Ne from LiF in order to measure the Debye-Waller Factor (DWF) at low surface temperatures. The analysis of the DWF temperature dependence yields detailed information on the nature of the interaction, and shows good agreement with the Levi-Suhl model for the DWF. © 1983.