Doppler-free kinetic energy release spectrum of

Abstract

A Doppler-free kinetic energy release spectrum of has been recorded using a coincident time-of-flight technique, resolving vibrational structure in the optically active A , D and D electronic states. A comparison is made with earlier photofragment and optical measurements. The v = 7 - 10 levels of the A state, dissociating into the lowest atomic level , are observed in the spectrum. The lifetime of the v = 7 level was determined to ns while the absence of lower levels indicates lifetimes above . The D state was found to support only two vibrational levels, dissociating into . The observed levels of the A and D states may dissociate either via tunnelling through the potential barriers separating the levels from the dissociation continuum or via electronic predissociation. Experimental data of the D state indicate that optical transitions into the state dominate the decay of the v = 0 level, while electronic predissociation dominates the decay of higher levels. For the v = 0 and 1 levels of the D state predissociation is observed into the and the ionic states, while predissociation into the states is observed for the v = 2 and 3 levels.