An experimental study of electronic excitation and electron capture processes in Rb(5 S-2(1/2)) collision with Cs+ and Li+ ions

The collisional systems Rb-Cs+ and Rb-Li+ (with all species in the ground e ntrance channel) have been studied using the crossed beams technique combin ed with decay fluorescence measurements. In the former system, only the emi ssions from the excited atoms Rb(5 P-2(1/2,3/2)) and Cs(7 P-2(1/2,3/2)) hav e 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 alka li atom-alkali ion collisional pairs. The collision energy-excitation cross section dependence for all four channels has been determined, as well as t he branching ratio between J-states for those involving Cs ions as projecti les. A qualitative interpretation of the observed inelastic processes is pe rformed using nb initio one-electron calculations.