PHOTODEPLETION AND DYNAMICS OF OXYGEN-ATOMS IN XENON MATRICES

The photodepletion and reaction dynamics of O atoms isolated in xenon matrices have been studied. Oxygen atoms are generated by 193 nm photo lysis of a N2O dopant and monitored via the laser-induced fluorescence of XeO exciplexes produced by the 248 nm excitation of Xe/O pairs. Di ssociative relaxation of XeO exciplexes generates energetic O atoms wh ich may travel significant distances in the matrix. This photoinduced mobility can lead to O atom loss. The O atom loss process is found to be bimolecular from 15 to 42 K at all fluences studied and is ascribed to an O+O recombination process. Higher temperature data (42 K) may e xhibit behavior characteristic of a transition from second order to fi rst order kinetics. A kinetic scheme is derived which can be used to m odel the data and infer a microscopic description of the O atom dynami cs.