INTERACTION OF ATOMS WITH SURFACE IN GRAZING COLLISIONS REGIME. THE MECHANISM OF DESORPTION. E.A.Andreev $^\ast$, F.I.Dalidchik $^\ast$, M.Y.Knignikov$^\ast$ $^\ast$ N.N.Semenov Institute of Chemical Physics, Russian Academy of Sciences,Kosygin str. 4, Moscow 117977, Russia The problem of vibration excitation of monolayer of physadsorbed atoms in regime of grazing collisions is considered. The mechanism of desorption induced by scattering atoms was investigated.