On the interpretation of rainbow scattering in gas atom/surface collisions

A model is proposed to explain the scattering of thermal energy atoms from surfaces. The model allows the behaviour of the scattering trajectories to be assessed. It is shown that when a collimated beam of Neon atoms is scattered from the LiF(100) surface, the peaks observed in the inplane distribution of scattered atoms versus angle of reflection arise from trajectories with one and two repulsive collisions with the same surface atom.