Single-Electron Capture into Ar+ Excited States in Ar2+ +Na Collision below 12 keV II. Relative Population Distribution in Ar+ Excited States

Excitation cross-sections are obtained for each term of the ArII n l -states ( n l =4 p , 4 p ' and 4 d ) at 4 and 8 keV. The relative population distribution among the terms of a given n l -state can be interpreted in terms of statistics based on the building-up principle of molecule under radial coupling scheme. The relative population distribution among the multiplets in a given term is proportional to their statistical weight; spin-orbit recoupling at large internuclear separations is responsible for the population mechanism. The energy dependence of excitation cross-sections is discussed in connection with the Landau-Zener theory.