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© 2015 American Physical Society. A high-spin isomer with τ>700 ns has been found in Hg204, populated in reactions of 1360-MeV Pb208 and 330-MeV Ca48 beams with a thick U238 target and a 1450-MeV Pb208 beam on a thick Pb208 target. The observed γ-ray decay of the isomer has established the yrast states below it, including another isomer with τ=33(3) ns. The experimental results are compared with shell-model calculations that include four holes in the configuration space between Sn132 and Pb208. The available spectroscopic information, including transition strengths, total conversion, and angular correlation coefficients, together with the observed agreement with the calculations, allows spin, parity, and configuration assignments to be proposed for the experimental states. The τ>700 ns isomer is the 22+ state of maximum spin available from the alignment of the four valence holes with the configuration πh11/2-2νi13/2-2.

The high-spin yrast structure of the 210Bi nucleus was investigated using -ray coincidence spectroscopy following deep-inelastic reactions in the 208Pb+208Pb system. Cascades of rays following the decay of a new isomer were identified. Spin-parity assignments to the states known from previous studies as well as to newly located excitations were made based on the measured angular distributions of rays combined with a transition conversion coefficient analysis.

This work reports the observation of high-spin states in 204Hg using time-correlated γ-ray spectroscopy to identify isomers populated in deep-inelastic collisions of a ~1.4 GeV 208Pb beam on a thick 238U target. A high-spin isomer with τ>1 μs has been found and the observed γ-ray decay has established the yrast states below it, including another isomer with τ=33(3) ns. Spin and parity assignments were based on conversion coefficients deduced from intensity balance and on the observed γ-decay patterns. The experimental results are compared with shell model calculations that include four holes in the entire configuration space between 132Sn and 208Pb. Observed agreement with the calculation gave the supplementary arguments to the spin-parity assignments and clarified configurations of experimental states. The τ>1 μs isomer is suggested to be the πh-2 11/2ν-2 13/2, 22+ states that results from the coupling to maximum spin available for the four valence holes. Few prompt transitions feeding the isomer were also observed.

New high-spin microsecond isomers, with Jπ=(31+) and Jπ=(28), have been identified in 206Bi at 10170 and 9233keV, respectively, using γ-ray coincidence spectroscopy following deep-inelastic reactions with the 76Ge+208Pb system. Yrast and near-yrast levels populated in the decay of these isomers have been located and interpreted with the help of shell-model calculations. The states identified at energies up to approximately 7 MeV can be described well in terms of one-proton-particle, three-neutron-hole couplings.

The high-spin structure of the neutron-rich 204Tl isotope has been studied up to a 11.2-MeV excitation energy and a I=30 spin range using the deep-inelastic heavy-ion γ-spectroscopy method with reactions of 48Ca on thick 208Pb and 238U targets. The established structure of yrast levels involves four isomeric states up to Iπ=22-, the highest spin state available for the maximally aligned four valence holes. The observations are interpreted and quantitatively confirmed by shell-model calculations. The rates of the identified M2 and E3 isomeric decays are discussed and a striking analogy is found for the yrast level structures and γ decays observed in the 18+ to 22- and 45/2- to 53/2+ spin ranges in 204Tl and 203Hg, respectively. In the highest spin part of the scheme, two prominently populated yrast states are tentatively identified as the 3 - 208Pb core excitation built on the 22- and 20 + maximally aligned four-hole states. Their energies are reproduced well by using energy shifts observed in experiments for the 208Pb core octupole excitation coupled to simpler intrinsic structures.

Gamma rays in the π-2ν2 nucleus 208Hg and π-1ν2 nucleus 209Tl have been studied at Gammasphere using deep-inelastic reactions induced by a 1360 MeV208 Pb beam on a thick 238U target. Previously unknown yrast γ-ray cascades above the 8+ and 17/2+ nanosecond isomers in 208Hg and 209Tl, respectively, were identified in coincidence with known γ rays deexciting the isomers. Yrast levels up to spin 13- in 208Hg have been located, and they are interpreted in light of the structure of the 210Pb isotone and with the help of shell model calculations. Shell model calculations by using the Vlow-k realistic interaction have been performed for 210Pb and 208Hg, and compared with experiment. The V low-k effective Hamiltonian seems to account well for the properties of these neutron-rich shell model nuclei.

The decay of a new, 53/2+, isomer at 8281 keV in Hg203 has been studied by γ coincidence spectroscopy. A half-life of 146(30) ns was measured. In addition, another isomeric, 39/2+, level with a half-life of 7.8(1.5) ns was observed. Some elements of the Rydstroem shell-model interaction have been adjusted to reproduce level energies in nuclei with two to four holes in the Pb208 core. With this interaction, the new states in the five-hole nucleus Hg203 are reproduced with an rms error of 105 keV.

Deep-inelastic reactions between a beam of 1360 MeV 208Pb ions and a thick 238U target have been used to populate the neutron-rich nucleus 211Pb. The observation of its γ decay has allowed identification of excited states up to the highest spin which can be formed from the three valence neutrons, including identification of three high-spin isomers. Level energies and transition strengths are compared to shell-model calculations with empirical interactions and predictions are made for the expected behaviour of more neutron-rich lead isotopes. The evidence for a possible increase in the neutron effective charge moving away from the N=126 shell gap is evaluated.

γ rays in the πν-1 nucleus 208Bi have been studied at the Gammasphere using deep-inelastic reactions induced by a 305-MeV 48Ca beam on a thick 208Pb target. Previously unknown yrast γ-ray cascades above the 10- millisecond isomer in 208Bi were identified in cross coincidence with known γ rays from complementary potassium products. Yrast and near-yrast levels up to 5.6 MeV in 208Bi have been located, and they are interpreted in light of earlier charged particle spectroscopy results, and with the help of shell model calculations.