Discovery of W-157 and Os-161
2010 (English)In: Physics Letters B, ISSN 0370-2693, Vol. 690, no 1, 15-18 p.Article in journal (Refereed) Published
The nuclides W-157 and Os-161 have been discovered ill reactions of Ni-58 ion beams with a Cd-106 target. The Os-161 alpha-decay energy and half-life were 6890 +/- 12 keV and 640 +/- 60 mu s. The daughter W-157 nuclei beta-decayed with a half-life of 275 +/- 40 ms, populating both low-lying alpha-decaying states in Ta-157, which is consistent with a 7/2(-) ground state in W-157. Fine structure observed in the alpha decay of Os-161 places the lowest excited state in W-157 with 1(pi) = 9/2(-) at 318 +/- 30 key. The branching ratio of 5.5(-2.2)(+3.1)% indicates that Os-161 also has a 7/2(-) ground state. Shell-model calculations analysing the effects of monopole shifts and a tensor force on the relative energies of 2f(7/2) and 1h(9/2) neutron states in N = 83 isotones are presented. (C) 2010 Elsevier B.V. All rights reserved.
Place, publisher, year, edition, pages
2010. Vol. 690, no 1, 15-18 p.
NUCLEAR REACTIONS Ni-58+Cd-106 at 290, 300, 310 MeV beam energy, gas-filled recoil separator, Si detectors, Measured E alpha, t(1/2), Deduced neutron single-particle configurations in Os-161, W-157, Shell model calculations
IdentifiersURN: urn:nbn:se:kth:diva-27290DOI: 10.1016/j.physletb.2010.04.056ISI: 000278933900003ScopusID: 2-s2.0-77953477653OAI: oai:DiVA.org:kth-27290DiVA: diva2:376947
QC 201012132010-12-132010-12-092010-12-13Bibliographically approved