We present a fully quantum-mechanical theory of the inelastic scattering of low-energy atoms from surfaces, based on the perturbation series and an expansion in numbers of phonons exchanged. Numerical calculations are carried out with a simple potential model and good agreement is obtained for the thermal attenuation of a helium beam by a close-packed surface of copper.

• Received 7 February 1984

DOI:https://doi.org/10.1103/PhysRevLett.53.1112