Temperature-dependent quantum yields for O(3P) and O(1D) production from photolysis of O3 at 248 nm

Abstract

A pulsed laser photolysis–resonance fluorescence technique was employed independently by two laboratories to measure Φ_O3P, the quantum yield for production of O(³P) from O₃ photolysis at 248 nm, between 196 and 427 K. The agreement between the two studies is very good, and the combined results are adequately represented by the function Φ_O3P= (0.115 ± 0.030) × exp((35 ± 60)/T) where the uncertainties are 2σ. Within experimental uncertainties, the new results are in agreement with previously reported room temperature results as well as with the single previous temperature dependence study, and greatly reduce the uncertainties in Φ_O3P(T) and Φ_O1D(T) (=1− Φ_O3P(T)) especially at temperatures other than room temperature. The yield of O(³P) in the reaction of O(¹D) with O₃ is shown to be greater than unity at room temperature and below, and to increase slightly with decreasing temperature.