Theoretical study of Na(3p) excitation in Na-Ne collisions

Abstract
Na(3p) excitation in Na-Ne collisions is analysed in terms of two independent mechanisms: (i) at low energy via two curve crossings leading to the simultaneous excitation of Ne atoms; (ii) at high energy by a direct transition. Diabatic potential energy curves and couplings are calculated using ab initio methods. The scattering equations are solved (quantally for mechanism (i) and by the impact-parameter method for mechanism (ii)). Total cross sections are calculated and agree reasonably well with the experimental results. In particular, the threshold behaviour is well reproduced by a seven-state model and at high energy the agreement between theory and experiment is improved with respect to previous work.