On the problem of rotational-state-dependent molecule-surface interaction:Relaxation, accommodation and trapping at low J

In the framework of a unified kinetic theory of particle-surface interactio ns, dependences of the relaxation, accommodation, and trapping of molecules on their angular momentum J are discussed. One of the basic parameters of the theory, the free flight time through the interaction region, is calcula ted using a simple model potential for which the classical equations of mot ion can be integrated analytically. With increasing J, an increase in molec ular relaxation and accommodation is predicted at small J, and a decrease a t larger J. These results constitute a microscopically founded interpretati on of recent experiments on surface light-induced drift. (C) 2000 American Institute of Physics. [S0021- 9606(00)00119-7].