Transition probabilities and branching ratios of Co II lines

Abstract

Absolute transition probabilities of 52 transitions of Co II with the upper levels belonging to the multiplets z 5F o, z 5G o and z 5D o have been obtained by determining branching ratios and by combining these with lifetime values measured by other authors. The branching ratios were found using intensity measurements with a special hollow electrode r.f. discharge. Some lines have also been measured using a phase method with a modified wall-stabilized arc in a spectro-interferometric arrangement. As for the lines belonging to the upper level multiplets z 3G o 5,4,3 there can only be found lifetime values in the literature that may be partly uncertain, the corresponding branching ratios are explicitly presented. In these cases preliminary absolute transition probabilities are estimated, as well as in the case of lines from the upper level multiplets z 3F o 4,3,2 and z 3D o 3,2,1, where lifetimes are not available in the literature.