Decay Study of Pb202m

Abstract

The decay of 3.62 hour Pb202m has been studied using high-resolution y-ray spectroscopy in an effort to elucidate its nuclear structure. Singles and y-y coincidence measurements were taken with the result that the previously suggested decay scheme was confirmed. In addition seven new y-ray transitions have been reported and five of these with energies of 124.75-, 211.88-, 417.44-, 601.95-, and 954.62-keV have been tentatively incorporated into this decay scheme with additional energy levels postulated at 1961 keV in Pb202 and at 1552 keV in the electron capture branch, T1202. Our placement of these transitions is at present still somewhat questionable, but with further analysis of the available data we hope to verify our preliminary assignments. Using transition intensities from this study and available conversion-electron intensities, we have also postulated a multipolarity of M1 for the 335-keV transition of T1202.