An experimental and theoretical study of electronic excitation and charge transfer processes in collisions between Cs(6~2S_(1/2)) atoms and Na~+(~1S_0) ions in the 0.30-4.00 keV energy range

摘要

The collisional system Cs + Na~+ with both species in their ground electronic state, has been studied using the crossed molecular beams technique and measuring the resulting fluorescent decay. Emissions from electronically excited Cs(6~2P_(3/2)) and Cs(7~2P_(1/2,3/2)) atoms have been detected as well as those from excited Na(3~2P_(1/2,3/2)) and Na(4~2D_(3/2,5/2)) produced by electron transfer. Cross-section values in the 0.30-4.00 keV energy range have been measured for the four different collision channels as well as the branching ratio between the resolved J-states for Cs(7~2P_(1/2,3/2)). A qualitative interpretation for some of the measured emission cross-sections as a function of the collision energy has been performed using ab initio one-electron calculations done for the (CsNa)~+ quasimolecule. Hemiquantal dynamical calculations have been carried out at selected collision energies including radial and angular non-adiabatic couplings, comparing the calculated cross-sections with the experimental data.