Thermal Equilibration of 176-Lu via K-Mixing

In astrophysical environments, the long-lived (\T_1/2 = 37.6 Gy) ground state of 176-Lu can communicate with a short-lived (T_1/2 = 3.664 h) isomeric level through thermal excitations. Thus, the lifetime of 176-Lu in an astrophysical environment can be quite different than in the laboratory. We examine the possibility that the rate of equilibration can be enhanced via K-mixing of two levels near E_x = 725 keV and estimate the relevant gamma-decay rates. We use this result to illustrate the effect of K-mixing on the effective stellar half-life. We also present a network calculation that includes the equilibrating transitions allowed by K-mixing. Even a small amount of K-mixing will ensure that 176-Lu reaches at least a quasi-equilibrium during an s-process triggered by the 22-Ne neutron source.Comment: 9 pages, 6 figure

Revised level structure of 120Te

The level scheme of the nucleus Te120, populated in the reaction Se80(Ca48,α4n), was reinvestigated using γ-ray coincidence data measured with the Gammasphere spectrometer. Previously, five high-spin rotational bands were discovered in this nucleus. Th

Multiquasiparticle states in the neutron-rich nucleus 174 Tm

Deep inelastic and transfer reactions with an 820-MeV, 136Xe beam and various ytterbium and lutetium targets have been employed to study high-spin structures in the neutron-rich thulium isotopes beyond 171Tm. Results in the doubly odd nucleus, 174Tm, inc

High-spin structure, K isomers, and state mixing in the neutron-rich isotopes 173 Tm and 175 Tm

High-spin states in the odd-proton thulium isotopes 173Tm and 175Tm have been studied using deep-inelastic reactions and γ-ray spectroscopy. In 173Tm, the low-lying structure has been confirmed and numerous new states have been identified, including a t

Anomalous isomeric decays in 174Lu as a probe of K-mixing and interactions in deformed nuclei

A Kπ=13+, 280 ns four-quasiparticle isomer in the odd-odd nucleus 174Lu has been identified and characterized. The isomer decays to both Kπ=7+ and Kπ=0+ rotational bands obtained from the parallel and antiparallel coupling of the proton 7/2+[404] and neutron 7/2+[633] orbitals. K mixing caused by particle-rotation coupling explains the anomalously fast transition rates to the 7+ band but those to the 0+ band are caused by a chance degeneracy between the isomer and a collective state, allowing the mixing matrix element for a large K difference to be deduced

Shape evolution in 116,118 Ru: Triaxiality and transition between the O(6) and U(5) dynamical symmetries

116Ru and 118Ru have been studied via β-delayed γ-ray spectroscopy of nuclei produced in fragmentation reactions at the Radioactive Ion-Beam Factory (RIBF) facility. Level schemes with positive-parity states up to spin J=6 have been constructed. The re

Isomers and excitation modes in the gamma-soft nucleus 192 Os

New spectroscopic results for high-spin states in 192Os populated in deep-inelastic reactions include the identification of a 2-ns, 12+ isomeric state at 2865 keV and a 295-ns, 20+ state at 4580 keV and their associated δJ=2 sequences. The structures ar

Three-quasiparticle isomers and possible deformation in the transitional nuclide, 195 Au

Deep-inelastic reactions and γ-ray spectroscopy have been used to study excited states in 195Au. A three-quasiparticle isomer with a mean-life of 18.6(3) μs has been assigned at 2461+Δ keV, with decays into newly identified structures. Possible config

Evolution of collective and noncollective structures in Xe-123

An experiment involving a heavy-ion-induced fusion-evaporation reaction was carried out where high-spin states of 123Xe were populated in the 80Se (48Ca,5n) 123Xe reaction at 207 MeV beam energy. Gamma-ray coincidence events were recorded with the Gammasphere Ge detector array. The previously known level scheme was confirmed and enhanced with the addition of five new band structures and several interband transitions. Cranked Nilsson-Strutinsky (CNS) calculations were performed and compared with the experimental results in order to assign configurations to the bands.Additional co-authors: T Lauritsen, S Zhu, A Korichi, P Fallon, B M Nyakó, and J Timá