DESORPTION OF METASTABLE PARTICLES INDUCED BY ELECTRONIC EXCITATION AT THE SURFACE OF RARE-GAS SOLID WITH PHYSISORBED HYDROGEN

The effect of physisorbed hydrogen on the desorption of metastable par ticles induced by electronic excitation from the surface of rare-gas. Solids (Ar, Kr, and Xe) was investigated systematically. When the surf ace of a rare-gas solid was exposed to a very small quantity of hydrog en at a temperature of about 30 K, in all cases, the desorption of hyd rogen metastables was observed, and new desorption species of Kr via cavity ejection process appeared in time-of-flight spectra for Kr. For Ar, although no significant increase of desorption yield was found, t he kinetic energy of Ar desorbed through cavity ejection process was increased by hydrogen adsorption. These results will be discussed in t erms of the change of electron affinity of the matrix and the interact ion between hydrogen and rare-gas molecules in excited states. (C) 199 8 American Vacuum Society.