Photofragment vector correlations by ion imaging: O2[a 1Δg(v, J)] from 248 nm dissociation of ozone

Abstract

Images of the two-dimensional projection of the nascent three-dimensional velocity distribution of O₂[a ¹Δ_g(v, J)] from the Hartley band (248 nm) dissociation of ozone have been obtained using resonance-enhanced multiphoton ionization coupled with time-of-flight ion imaging. These projections show strong evidence of v–J correlation. The two-dimensional (2D) images were simulated using a Monte Carlo forward convolution program that accounts for the dependence of the detection efficiency on angular momentum polarization, and uses the final O₂ rotational level as the only adjustable parameter. The experimental results are accurately reproduced assuming an impulsive dissociation from the ground-state geometry (β= 1.18). The results suggest generally that the ion-imaging technique may be readily exploited in studies seeking to quantify product angular momentum polarization, and may be useful for both photodissociation and collision experiments.