Kinetic theory of rotating molecule interaction with a solid surface

A kinetic theory of interaction between molecules with rotational degrees of freedom and a solid surface for arbitrary ratios among the times of molecule rotation, flight through the region of surface forces, and relaxation of a molecular ensemble due to phonons has been developed. A kinetic equation for an ensemble of molecules residing in the field of surface forces has been derived from the equation for the one-particle distribution function of molecules by averaging it along the dynamical trajectories in the region of surface force action. A simple analytic expression for the probability of trapping a molecule with rotational degrees of freedom has been obtained. Experimental data on rotational cooling and rotational polarization of desorbed molecules are discussed.