Relaxation Processes of Translationally Hot O(1D) by Collisions with O2

Abstract

The collisions of translationally hot O(1D) with O2 result in two processes, translational energy relaxation and electronic quenching to O(3P). These two processes were studied in a gas cell at room temperature using the vacuum ultraviolet laser-induced fluorescence technique. The initial hot O(1D) atoms were produced by the photodissociation of N2O at 193 nm, which have average translational energies of 18.1 kcal mol-1 in the laboratory frame. Time-resolved measurements of the Doppler profiles for the hot O(1D) atoms revealed the translational energy relaxation process, whereas the quenching process was investigated by measuring both the decrease of the O(1D) concentration and the increase of the product O(3P) concentration at various delay times after the photochemical formation of the hot O(1D) atoms. From the simulation employing an elastic hard-sphere collision model with a Monte Carlo method, the hard-sphere diameter for the translational energy relaxation process of hot O(1D) by collisions with O2 ...