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The core-excited isomer in fully-ionized 133Sb has been directly studied for the first time by applying the\ud novel technique of isochronous mass spectrometry at GSI. The neutron-rich nuclides in high charge states\ud were produced by projectile fission of 411 MeVA 238U ions, separated in flight by the fragment separator\ud (FRS) and stored in the isochronous storage ring (ESR). The measured excitation energy is 4.56(10) MeV.\ud The neutral-atom half-life is known to be 17 μs. This is the shortest-lived isomer measured directly with\ud mass spectrometry techniques. The extended in-flight half-life of the bare ions in the ESR, which is due\ud to the exclusion of the strong internal conversion, demonstrates that there should be another nuclear\ud level above that identified from isomer-decay spectroscopy, in support of shell-model calculations. This\ud measurement opens up a new half-life domain for storage-ring measurements

The four proton-hole nucleus, 204 Pt, was populated in the fragmentation of an E/A = 1 GeV 208 Pb beam. The yrast structure of 204 Pt has been observed up to angular momentum I = 10 by detecting delayed γ-ray transitions originating from metastable states. These long-lived excited states have been identified to have spin-parities of I π = (10 + ), (7 − ) and (5 − ) and half-lives of T 1/2 = 146(14) ns, 55(3) µs and 5.5(7) µs, respectively. The structure of the magic N = 126 204 Pt nucleus is discussed and understood in terms of the spherical shell model. The data suggests a revision of the two-body interaction for N = 126, Z < 82, which determines the evolution of nuclear structure towards the r-process waiting point nuclei.PACS numbers: 29.30. Kv, 23.20.Lv The evolution of the properties of atomic nuclei with respect to neutron and proton numbers is a key question of nuclear physics. The study of unstable, neutron-rich nuclei represents one of the foremost pursuits of modern nuclear physics. Over the coming decade new radioactive ion beam facilities are being built with the main objectives being to probe neutron-rich nuclei. Within recent years surprising phenomena have been observed in neutron-rich nuclei such as neutron skins, halos and dramatic changes in the ordering and spacing of energy levels [1].While the stability of the N = 82 shell gap is an active topic of research [2,3], an open question is whether or not there is a quenching of the N = 126 shell gap as protons are removed from doubly magic 208 Pb. The proton dripline has been experimentally reached up to heavy elements [4], our present knowledge of the neutron dripline is limited to light species. The part of the nuclear chart with the least information on neutron-rich nuclei is the 76 Os to 82 Pb region, with experimental knowledge on only a few isotopes. This mass region is however an ideal testing ground of nuclear theories. With the removal of just a few protons and neutrons the landscape evolves from spherical to elongated prolate through disk shaped oblate and triaxial forms [5]. Consequently the information gained on neutron-rich, N = 126 nuclei is essential for the understanding of nuclear structure in heavy nuclei. From a longer-term perspective, experi-