Experiments at the Gas-Surface Dynamics Laboratory in Trento (IT) show that internal degrees of freedom of a spherical molecule play an important role in energy transfer processes with corrugated surfaces. Up to now mainly thermally excited beams have been used in the scattering experiments. There is great interest extending them to the investigation of the mode specificity of the observed effects. Multi-photon excitation of the beams, by a cw high power CO, laser, will provide highly vibrationally excited molecules and their energy transferred in the collision is studied with the opto-thermal method.
The actual determination of the rovibrational state of the molecules after the collision is a more difficult task. LIF and REMPI detection is explored to characterize the final state at least from the point of view of the vibrations.
The energy transfer mechanism will also be studied by changing the characteristics of the surface. A second molecular beam is used to adsorb different species on the surface starting from inert up to reactive species.