Excited States inPb206from the Decay ofBi206

Abstract
Chemically separated and isotopically separated sources of 6.2-day Bi206 produced by the (p,xn) reactions on lead were used to study the excited states of Pb206. γ-ray data were taken with a Compton-suppression spectrometer and with a Ge(Li)-Ge(Li) two-parameter analyzer system. From these, 66 γ rays were identified in the decay of Bi206 and 61 of these transitions have been placed from coincidence results, energy sums and differences, and intensity considerations in a decay scheme with 19 excited states. New levels at 2826.4, 2939.6, 3225.5, and 3244.1 keV have been deduced. Spins and parities for all but one excited state were deduced from published internal-conversion electron intensities, relative γ-ray intensities, logft values, and existing angular distribution measurements from particle reactions. The branching ratios, transition multipolarities, and lifetimes for many of the Pb206 levels were calculated by using the wave functions that result from shell-model calculations with phenomenological as well as realistic interactions, and calculations using the two-nucleon random phase approximation.