An experimental study of electronic excitation and electron capture processes in Rb(5 2S1/2) collision with Cs+ and Li+ ions

The collisional systems Rb-Cs+ and Rb-Li+ (with all species in the ground entrance channel) have been studied using the crossed beams technique combined with decay fluorescence measurements. In the former system, only the emissions from the excited atoms Rb(5 P-2(1/2,3/2)) and Cs(7 P-2(1/2,3/2)) have been observed, while for the latter the electron exchange channels Li(2 P-2(1/2,3/2)) and Li(3 P-2(1/2,3/2)) were present, all of them giving signal strengths much lower than those shown by the same processes for other alkali atom-alkali ion collisional pairs. The collision energy-excitation cross section dependence for all four channels has been determined, as well as the branching ratio between J-states for those involving Cs ions as projectiles. A qualitative interpretation of the observed inelastic processes is performed using nb initio one-electron calculations.