PHOTO-DISSOCIATION OF BR2 IN THE VISIBLE CONTINUUM

The photodissociation of Br2 in the region 434-511 nm has been studied using the technique of laser induced photodissociation spectroscopy. Following photolysis of Br2 with a tunable dye laser, production of bromine atoms in the electronically excited, 42P1/2, and ground, 42P3/2, states was monitored by observing the attenuation of the atomic resonance emission line, 52P 3/2→42P3/2, at 148.9 nm. Analysis of the absorption profiles yielded the relative contribution to the visible continuum of the B3Π0+u,←X1Σ g+ transition. Estimates of the absolute absorptivity for the transitions 1Π1u, B3Π0 + u, A3Π1u ←X 1Σg + were obtained by application of the reflection principle. These results are in excellent agreement with previous direct measurements but suggest that models of the Br2 absorption continuum which neglect the A 3Π1u, ← X 1Σg + transition are likely to be in error. © 1979 American Institute of Physics.