Excited levels in Po and Pb fed by β-decays of Bi (T1/2 = 45.6 min) and Tl (T1/2 = 2.2 min)

The γ-decay of radiochemically separated ²¹³Bi sources (T_1/2 = 45.6 min), in equilibrium with ²⁰⁹Tl (T_1/2 = 2.2 min) and ²¹³Po (T_1/2 = 4.2 μs), has been reinvestigated using coaxial HPGe detectors, a LEPS detector and the γ-γ coincidence method. The energies and intensities of 20 γ-lines were measured, of which 11 are reported for the first time. Of the ten γ-rays attributed to ²¹³Bi β-decay, five are new. All of them were interpreted in a ²¹³Po level scheme using γ-γ coincidence data. New levels at 292.8, 1003.6 and 1119.5 keV are proposed in ²¹³Po. In the ²⁰⁹Tl β-decay, five γ-lines were measured, two of which are new. On the basis of γ-γ coincidence, we suggest that two new levels of 3069.6 and 3388.9 keV are fed into the ²⁰⁹Pb magic nucleus.