A. Astier

High-spin structures of 124−131Te: Competition of proton- and neutron-pair breakings

The 124-131Te nuclei have been produced as fission fragments in two fusion reactions induced by heavy ions ( 12C + 238U at 90MeV bombarding energy and 18O + 208Pb at 85MeV) and studied with the Euroball array. Their high-spin level schemes have been extended up to 6MeV (even-A and 5MeV (odd-A excitation energies from the triple

High-spin states with seniorityv=4, 5, and 6 in119–126Sn

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High-spin structures of five N = 82 isotopes: 54 136 Xe, 55 137 Cs, 56 138 Ba, 57 139 La, and 58 140 Ce

-ray coincidence data. The

Coexistence of “ \alpha + 208Pb ” cluster structures and single-particle excitations in 212 84Po128

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High-spin structures of3688Kr52and3789Rb52: Evolution from collective to single-particle behavior

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High-spin structures of55136Cs81

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High-spin structures of the odd-A4397−105Tc isotopes

angular correlations have been analyzed in order to assign spin and parity values to most of the observed states. Moreover the half-lives of isomeric states have been measured from the delayed coincidences between the fission-fragment detector SAPhIR and Euroball, as well as from the timing information of the Ge detectors. The behaviors of the yrast structures identified in the present work are first discussed in comparison with the general features known in the mass region, particularly the breakings of neutron pairs occupying the

Low collectivity of the first 2+ states of 212,210Po

\nu

A revised B(E2;2+1

h11/2 orbit identified in the neighboring Sn nuclei. The experimental level schemes are then compared to shell-model calculations performed in this work. The analysis of the wave functions shows the effects of the proton-pair breaking along the yrast lines of the heavy Te isotopes.

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The 119-126Sn nuclei have been produced as fission fragments in two reactions induced by heavy ions: 12C+238U at 90 MeV bombarding energy, 18O+208Pb at 85 MeV. Their level schemes have been built from gamma rays detected using the Euroball array. High-spin states located above the long-lived isomeric states of the even- and odd-A 120-126Sn nuclei have been identified. Moreover isomeric states lying around 4.5 MeV have been established in 120,122,124,126Sn from the delayed coincidences between the fission fragment detector SAPhIR and the Euroball array. The states located above 3-MeV excitation energy are ascribed to several broken pairs of neutrons occupying the nu h11/2 orbit. The maximum value of angular momentum available in such a high-j shell, i.e. for mid-occupation and the breaking of the three neutron pairs, has been identified. This process is observed for the first time in spherical nuclei.