On the [formula omitted] state of NaK

Abstract

The C 1 Σ + state of NaK has been observed up to v ′′=72 in a compilation of measurements from resolved laser induced fluorescence and polarisation labelling spectroscopy experiments. Resolved fluorescence experiments followed single colour optical–optical double resonance (sometimes with the source placed inside a dye laser cavity), or two-colour double resonance using two infrared dye lasers, which excited either the 6 1 Σ + or 3 1 Π electronic states. Fourier transform resolved fluorescence spectra show that low vibrational levels of the 3 1 Π state are efficiently depopulated by collisional electronic energy transfer to nearby vibrational levels of 6 1 Σ + . Equilibrium constants for the C 1 Σ + state of NaK are: T e =17786.75 cm −1 (with respect to the minimum of the electronic ground state), Y 10=69.6123 cm −1, Y 01=0.05919 cm −1.