Very low-energy scattering of helium atoms from crystal surfaces. A quantitative comparison between experiment and theory

Abstract

Very low-energy scattering experiments are described for He atoms colliding with an LiF(001) surface. The apparatus is capable of performing experiments for beam energies down to 4 meV. The He–LiF results are compared with close-coupling calculations on the interaction potential of Celli et al.(J. Chem. Phys., 1985, 83, 2504). Very good agreement between experiment and theory is found, but there are small discrepancies which should allow the potential to be refined.