Nuclear Data Sheets for A=187

Evaluated spectroscopic data and level schemes from radioactive decay and nuclear reaction studies are presented for Hf-187, Ta-187, W-187, Re-187, Os-187, Ir-187, Pt-187, Au-187, Hg-187, Tl-187, Pb-187, Bi-187, and Po-187. This evaluation for A=187 supersedes the earlier one by R. B. Firestone (1991FiO(2)) published in Nuclear Data Sheets 62, 159 (1991) and the Tl-187 evaluation by C. M. Baglin (1999Ba24) published in Nuclear Data Sheets 86, 487 (1999). Highlights of this publication are the following: This evaluation includes first identifications of Hf-187, Ta-187 (1999Be63, 2000PoZY) and Po-187 (2006An11) nuclides. A B(E2)up arrow=0.080 12 was determined by 1967Bi10 for the 9/2+ state at 845 keV in Re-187 Coulomb Excitation. Using this B(E2) value and the adopted 845 gamma ray properties, a T-1/2=54 fs 34 can be deduced for the 845 keV level of Re-187. This T-1/2 Yields a large B(E2)(W.u.) = 1.3x10(5) for the 263 gamma (depopulating the same level) indicating either substantial unobserved feeding or incorrect g-ray branching intensities of this level. The decay of g.s. and isomer of Tl-187 are poorly known (please see Tl-187 epsilon decay (51 s+15.60 a)). Based on Po-191 alpha decay Studies, 2002An19 establishes a Pb-187 isomeric level energy at 2(15) keV and assigns J pi=13/2+ for the Pb-187 g.S. and J pi=3/2- for the isomeric state (inverse of the systematics of odd-mass Pb nuclei in this region). From Pb-187 and Pb-187(m) mass measurements, 2005We11 determined the isomeric level energy at 33(13) keV.