Quantal close-coupling calculations on fine-structure transitions in rubidium-neon collisions

Abstract

Fully quantal close-coupling calculations of the cross sections for fine structure and depolarization transitions in Rb(S2P)-Ne collisions are presented. The calculations proceed by analogy with collision-induced rotational excitation (Reid and Dalgarno (1970)). They were performed using the interaction potentials of Baylis (1969) and of Hidalgo and Geltman at both high and low energy. The quantal calculations using the Hidalgo-Geltman potential are compared with the Hidalgo-Geltman semi-classical calculations and are found to be in reasonable agreement. The Baylis potential gives good agreement with experiment for the depolarization cross sections and the low-energy inelastic cross section. Improvement in the repulsive potential should improve the high-energy inelastic results. The results suggest that Nikitin's second mechanism (1967) (Coriolis coupling between the Pi quasi-molecular states at short interatomic distances) is to be favoured over the first (coupling between the Pi 1/2 and Sigma 1/2 states at intermediate distances) for Rb-Ne collisions.