DECAY KINETICS OF XECL(B,C) IN XE AND IN MIXTURES OF XE WITH KR, AR, NE, AND HE

The two-photon, laser-assisted reaction between Xe and Cl2 has been used to prepare XeCl (B,C) molecules in Xe and in Xe mixtures with lighter rare gases for kinetic studies of the coupled XeCl (B,C) states. The XeCl (B-X) spectra were used to assign the conditions for which the vibrational temperature was nearly 300 K. Relative intensity and coupled radiative lifetime measurements provide independent data which support an energy separation between the XeCl(B) and XeCl(C) states of ∼100 cm-1. The two-body quenching rate constant in Xe for XeCl (B,C) was measured as 5-2 +3 × 10-12 cm3 s-1, and a three-body quenching rate constant of 13 ± 4×10-31 cm6 s-1 is indicated. Experiments also were done with added Kr, Ar, Ne, and He to establish two-body and mixed (e.g., Xe + Ar) three-body quenching rate constants. The three-body quenching rate constants are nearly equal to the Xe2 Cl* formation rate constants and three-body dark quenching of XeCl(B,C) is negligible. © 1990 American Institute of Physics.