Edinburgh Research Explorer

New proton radioactivities Ir and Au

Research output: Contribution to journalArticle

  • C.N. Davids
  • P.J. Woods
  • J.C. Batchelder
  • C.R. Bingham
  • D.J. Blumenthal
  • L.T. Brown
  • B.C. Busse
  • L.F. Conticchio
  • T. Davinson
  • S.J. Freeman
  • D.J. Henderson
  • R.J. Irvine
  • R.D. Page
  • H.T. Penttilä
  • D. Seweryniak
  • K.S. Toth
  • W.B. Walters
  • B.E. Zimmerman

Related Edinburgh Organisations

Original languageEnglish
Pages (from-to)2255-2266
Number of pages12
JournalPhysical Review C
Volume55
Issue number5
DOIs
StatePublished - 1 May 1997

Abstract

The new proton radioactivities Ir and Au have been observed. The Ir isotopes were produced via the Mo(Kr,pxn)Ir reactions at 357 and 384 MeV. Au was produced via the Ru(Kr,p2n)Au reaction at 389 MeV. The proton emitters were each identified by position, time, and energy correlations between the implantation of a residual nucleus into a double-sided silicon strip detector, the observation of a decay proton, and the subsequent observation of a decay alpha particle from the daughter nucleus (Os and Pt, respectively). Both Ir and Ir have proton-emitting ground and isomeric states, which also decay by alpha emission. The proton-decay rates have been reproduced by calculations using the WKB barrier penetration approximation and a low-seniority shell-model calculation of the spectroscopic factors. The alpha decays of the four nuclei are followed by chains of alpha decays, allowing the determination of single-particle orbital orderings. Mass information has also been obtained from the alpha-decay chains because a connection to a known mass can be obtained for one of the nuclei. Ground-state mass excesses are reported for Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, and Pt. The mass excess for Au is also given. Proton separation energies are also deduced for the odd-Z alpha daughter nuclei of the Ir proton emitters.

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