Studies of Perturbations Using Time Resolved Techniques

Perturbations in a wide sense cover a wide range of various phenomena which are consequences of interactions between close lying molecular levels. Time resolved spectroscopy, which is mainly developed during the last decade, is particularly well suited for studies of a number of these phenomena. Thus, for instance, ordinary mixing of two levels changes their lifetimes and frequently in such a way that the mixing coefficients may be deduced. Addition of catalyzer gases might cause a collision induced transfer between perturbing levels. However, similar transfer processes might also occur with high probability between non-perturbing levels which change the decay curves drastically allowing determinations of involved rate coefficients. Interactions between attractive state levels above the dissociation limit and levels in the continuum of repulsive as well as other attractive states give rise to various kinds of predissociations which can be studied with very high sensitivity using time resolved spectroscopy.