A semiclassical study of He, Ne, and Ar sticking on metal surfaces

A semiclassical study is made of He, Ne, and Ar sticking on a model Cu surface. A fully quantum formulation for gas-phonon scattering is modified to describe the motion of the gas particle semiclassically, via the use of a Gaussian wave packet. The phonons are treated quantum mechanically. Probabilities for energy transfer and trapping are derived. Trapping is studied as a function of particle mass, energy, surface temperature, the depth of the attractive well, and the shape of the repulsive part of the potential energy surface. The limit of low surface temperature and beam energy is discussed. A comparison is made with the forced oscillator model, another semiclassical formulation.