Collisional redistribution and fine-structure transitions in Na–Ar optical collisions

Abstract

Cross sections for optical collisions between Na and Ar are calculated for a range of detunings and a single collision energy. Results are obtained from a fully quantum mechanical coupled channels calculation including the ground and three excited molecular states. The effects of fine-structure transitions between the excited states during dissociation of the molecule following absorption determine the relative intensities of the two Na fluorescence lines. The calculated intensity ratios are compared to measured results. A quasiclassical model also is presented and is shown to produce total absorption line shapes in excellent agreement with the quantum mechanical results.