Donald H. Levy

The dispersed fluorescence spectrum of NaAr: Ground and excited state potential curves

The van der Waals molecule NaAr has been prepared by supersonic free jet expansion of a mixture of sodium, argon, and helium. The A 2Π←X 2Σ+ electronic transition has been excited by a tunable dye laser and the resulting A→X fluorescence has been studied. The dispersed fluorescence spectra display both discrete and diffuse features, corresponding to transitions from excited vibrational levels of the A state to bound and unbound levels of the X state. The characteristic reflection structure in the bound‐free spectra permits an unambiguous assignment of the vibrational numbering in the A state. This assignment and the previously measured spectroscopic constants are used to calculate the potential curve of the A state. The discrete structure in the fluorescence spectra is analyzed and, together with the previous measurements, is used to determine the potential curve of the X state in the well region. The repulsive part of the X curve is then deduced through trial‐and‐error simulation of the biund‐free spectr...