ELASTIC AND INELASTIC-SCATTERING OF NEUTRAL ATOMS BY A CORRUGATED HARD WALL

A general treatment of the elastic and inelastic scattering of neutral atoms by a corrugated hard wall potential is presented. The influence of the atomic thermal motion is divided into two parts, one corresponding to a translation of the whole profile and due to long wavelength phonons, and the other inducing a deformation of the potential shape corresponding predominately to short wavelength phonons. The Debye-Waller factor (for both the elastic and inelastic contributions) has the expected form and contains terms which correspond to a translation of the profile. However a correction term is introduced by the profile deformation. The one phonon exchange can occur with all the crystal phonons but it appears more important with those of long wavelength. The inelastic cross section is expected to be larger in the vicinity of diffracted peaks of large intensity. The only approximation is made in the determination of the source function where one supposes that a limited and small amount of energy is exchanged between the particle and the crystal. © 1979.