Laser induced thermal desorption from surfaces.

Non-resonant laser induced desorption of adsorbed molecules from surfaces has been simulated using the stochastic trajectory technique. An NO molecule is initially bound to a cold LiF (100) surface. Rapid heating of the surface is then simulated via random forces applied to the edges of the 32 atom surface slab. When the rate of heating is rapid compared to the rates of thermalization of the degrees of freedom of the molecule, it is found that the translational, rotational and vibrational degrees of freedom of the desorbing molecule are significantly colder than the temperature of the surface at the instant of desorption.