ELECTRON-CAPTURE PROCESSES IN THE COLLISION BETWEEN RUBIDIUM IONS ANDSODIUM NEUTRAL ATOMS BY CROSSED MOLECULAR-BEAMS

Electron capture processes in the collision between rubidium ions and sodium metal atoms, leading to Rb(5 P-2(1/2,3/2)) and Rb(6 P-2(1/2,3/2 )), have been studied by measuring the fluorescent emission of the exc ited species formed in a crossed beam experiment. Total cross sections have been determined in the 0.35-5.0 keV energy range. The [Rb(5 P-2( 1/2,3/2)) --> Rb(5 S-2(1/2))] electronic transition has been resolved into its spin-orbit components and magnetic cross sections have been d etermined by polarization measurements. The total cross section for bo th channels have been interpreted by empirical fittings using a linear Landau-Zener-Stuckelberg model and also by qualitative analysis of re cent ab initio calculations. (C) 1997 Elsevier Science B.V.