Radiative lifetimes, branching ratios and absolute transition probabilities of atomic uranium by delayed photoionization measurements

Radiative lifetimes of ten even-parity energy levels of atomic uranium in the 15,500–19,000 cm −1 region and branching ratios of six transitions originating either from ground level ( 5 L 6 o ) or from lowest metastable level ( 5 K 5 o ) at 620.32 cm −1 are measured employing three-step delayed photoionization technique. The lifetimes of five energy levels and branching ratios of five transitions are measured for the first time. By combining the experimentally measured values of radiative lifetimes and branching ratios, we have determined the absolute transition probabilities of six transitions of uranium and compared with those previously reported in the literature.