Accession Number : AD1032026


Title :   Nuclear Structure of 186Re


Descriptive Note : Technical Report


Corporate Author : AIR FORCE INSTITUTE OF TECHNOLOGY WRIGHT-PATTERSON AFB OH WRIGHT-PATTERSON AFB United States


Personal Author(s) : Matters,David A


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/1032026.pdf


Report Date : 24 Dec 2016


Pagination or Media Count : 164


Abstract : The unstable odd-Z, odd-N isotope 186Re exists in a mid-shell deformed region of the chart of the nuclides where long-lived nuclear isomers are common. 186Re (ground-state half-life T1/2=3.7186 d) has an isomer with a half-life of approximately 2.0 x 10(5) y. The 186mRe isomer is a candidate energy-storage medium for a radioisotope power source of military importance that would operate on the principle of isomer depletion. Data about levels and transitions above the 186mRe isomer, absent from the adopted level scheme for 186Re, are needed to identify a means of depleting the isomer. Four experiments were performed to investigate the 186Re level structure, which involved three different reactions: 187Re(n,2ngamma)186Re, 185Re(n, gamma)186Re, and186W(d,2ngamma)186Re. In each of these experiments, gamma-ray spectra from the decay of excited states in 186Re were measured and analyzed to reveal information about the discrete-level structure of 186Re. This work resulted in new information about gamma-ray transitions that feed the 186mRe isomer, an improved value for the excitation energy of the isomer, independent measurements of the 186Re neutron-separation energy and the cross section for thermal-neutron capture on 185Re, and numerous gamma-ray transitions and levels in 186Re which are not included in the adopted level scheme.


Descriptors :   nuclear reactions , nuclear structure , nuclear isomers , rhenium , quantum numbers


Subject Categories : Nuclear Physics & Elementary Particle Physics
      Metallurgy and Metallography


Distribution Statement : APPROVED FOR PUBLIC RELEASE