Mean lives andgfvalues in Ui

Determinations of the mean lives of the 27887- and 16900-cm^-1 levels in Ui have been made, each at a single vapor density, using electronic excitation and a method of delayed coincidence. The lifetime values were obtained by optically detecting the decays of the 3584.9- and 5915.4-{} resonance transitions, respectively. Using branching ratios obtained from known relative f values, the averages of the measured lifetimes were corrected for imprisonment of the resonance radiation giving the following results: τ₀²⁷⁸⁸⁷=10.9±0.8 ns and τ₀¹⁶⁹⁰⁰=205±20 ns. These mean lives were then used to place a system of relative gf values on two independent absolute scales, which were found to be in very close agreement. The lifetimes and gf values are presented in comparison with the experimental results of others.