Abstract.A new approach for the understanding of the energy relaxation dynamics of excited atoms involving a long-lived molecular precursor is presented here for krypton. Excitation of the gas close to the 5s[3/212 metastable atomic level (Eat . --E .... < kT) is achieved with an intense VUV laser source (I m 10 ~2 photon/pulse) realized by resonantly enhanced 4-wave mixing (2o91 + 092) in room temperature mercury vapor (NHg~10 a3 at./cm3). The decay of the II. continuum luminescence (145 nm) is studied. In the pressure range 200-500 mbar, decay rates depend linearly on pressure but have a negative zeropressure intersect. We show here that this result can be understood as an effect of the exchange of energy between two different "reservoirs" of atomic (5 s [3/2]2) and molecular (lg) nature, and can be an inherent peculiarity of the recombination kinetics of excited atoms with several product channels. The efficiency of the model is checked for the Kr/N2 system. Rate constants for relaxation processes are determined in pure krypton and in Kr/N2 mixtures.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.