TEMPERATURE-INDUCED MOBILITY AND RECOMBINATION OF ATOMIC OXYGEN IN CRYSTALLINE KR AND XE .1. EXPERIMENT

Recombinant molecular spectra of O2 in crystalline Kr and Xe, obtained from sudden recombination induced by laser pumping of the predissocia tive B state, and by adiabatic recombination induced thermally, are re ported. All electronic states that correlate with O(3P) + O(3P) are po pulated by both methods in Kr. The excited triplet states are strongly perturbed in Xe. Laser induced fluorescence (LIF) spectra of atomic O are also reported. Two emissions are observed in Kr; one at 563 nm wi th a radiative lifetime of 11 mus, and another at 599 nm with a radiat ive lifetime of 1.4 mus. These are assigned to emissions from neutral O(1S) trapped in substitutional and interstitial octahedral sites, res pectively. O atoms are generated in situ by photodissociation of eithe r O2 or N2O. The subsequent thermally induced recombination of atoms i s followed using LIF from atomic centers and molecular thermoluminesce nce. The recombination follows first order kinetics, from which it is inferred that atomic mobilities are characterized by long-range migrat ion, with migration lengths of greater-than-or-equal-to 300 angstrom. Site specific Arrhenius rate constants are extracted from the analysis of glow curves. Only two sites, interstitial and substitutional O(h), contribute to the glow curves in crystalline Kr. A third site is pres ent in crystalline Xe. A broad distribution of activation energies is observed in vapor deposited matrices.