A laser-based O atom beam source together with state-resolved detection techniques are used to characterize the energy transfer dynamics of ground (3PJ) and electronically-excited (1) state O atoms interacting with a fused silica surface. Time-of-flight spectra of the incident beam and scattered O atoms are measured, and provide detailed information regarding state-resolved angular and velocity distributions. We find a significant degree of thermalization (angular, fine structure state and velocity distributions) in the scattered O(u3P) atoms. The survival probability of O(1) is determined to be 0.01, and the probability for O(u1) quenching to super-elastic O(u3P) is 0.05. Given that the measured probability for radiative quenching of 1 is not significant ( 0.001), these results indicate that the majority of the available energy in the incident O atoms (both u3P and 1D) is transferred to the substrate. The implications of the scattering/energy transfer dynamics with respect to the O atom/fused silica surface interactions are discussed.
Citation: Journal of Chemical Physics
Issue: No. 1
Pub Type: Journals
atomic oxygen, electronic state quenching, fused silica, gas-surface scattering, O atom Surface reaction, REMPI, state-resolved dynamics