Reactive Quenching of Two-Photon Excited Xenon Atoms by Cl sub 2

摘要

Total binary and tertiary quench rates have been measured for the reaction Xe (5p sup 5 6p) + Cl sub 2 at thermal temperatures. Xenon atoms are excited by state-selective, two-photon absorption with a uv laser. The time dependent fluorescence from the excited atom in the IR and from XeCl* (B) product near 308 nm have been measured with subnanosecond time resolution. The decay rates are measured as a function of Cl sub 2 pressure to 20 Torr and Xe pressure to 400 Torr. The measured reaction rates (k sub 2 approx. 10 sup -9 cm sup 3 sec sup -1 ) are consistent with a harpoon model described in a separate paper. We also measure large termolecular reaction rates for collisions with xenon atoms (k sub 3 approx. 10 sup -28 cm sup 6 sec sup -1 ). Total product fluorescence has been examined using a gated optical multichannel analyzer. We measure unit branching fractions for high vibrational levels of XeCl* (B) with very little C state fluorescence observed. The measured termolecular rates suggest similar processes will dominate at the high buffer-gas pressures used in XeCl lasers. The effect of these large reactive cross sections for neutral xenon atoms on models of the XeCl laser will be discussed. (ERA citation 13:016547)