Simulation of the bound-free KrF* emission spectra from reactive quenching of Kr(5s[3/2]2) and Kr(5s[3/2]1) atoms

Abstract

The low pressure KrF emission spectra, which includes the KrF(III,1/2−I,1/2 or B–X) and the KrF(II,3/2−I,3/2 or C–A) transitions arising from the reaction of metastable or resonance states of Kr with F₂, NF₃, and CF₃OF, have been simulated by computer. Since a broad distribution of very high v′ levels is produced by the chemical reactions, the dependence of the spectrum upon various properties of the upper and lower states was first investigated. A general discussion of the types of emission spectra that can be expected from bound‐free transitions from high v levels is first presented. As a starting point for fitting the KrF spectra, the ab initio potential curves and the dependence of the transition moments upon internuclear separation calculated by Hay and Dunning for KrF were used. The I,1/2 and III,1/2 curves are generally satisfactory but some modification of the I,3/2 potential curve was necessary in order to fit the observed spectra. As the final step, KrF* vibrational distributions from the Kr*+F₂, CF₃OF, and NF₃ reactions were assigned that gave simulated spectra in agreement with the low pressure spectra. The fraction of the available energy released as KrF* vibrational energy was ≳50%. The assignment of the initial vibrational distribution as well as 〈f_V〉, and to the dependence of the transition moment upon internuclear separation. Within some general limitation, this spectrum is not very sensitive to the I,1/2 or III,1/2 potential curves.