[en] We study for the first time the internal structure of Te-140 through the beta-delayed γ-ray spectroscopy of Sb-140. The very neutron-rich Sb-140 nuclei with Z = 51 and N = 89 were produced by the in-flight fission of ²³⁸U beams at the Radioactive Isotope Beam Factory, RIKEN. The half-life and spin-parity of ¹⁴⁰Sb are reported as 173 ± 12 ms and 3^-, respectively. In addition to the excited states of ¹⁴⁰Te produced by the beta-decay branch, the beta-delayed one-neutron and two-neutron emission branches were also established. By identifying the first 2⁺ and 4⁺ excited states of ¹⁴⁰Te, we found that Te isotopes persist in their vibrator character with E(4⁺)/E(2⁺) = 2. We discuss the distinctive features manifest in this region revealed in pairs of isotopes with the same neutron holes and particles with respect to N = 82. (authors)

[en] The techniques used to produce a ^177mLu (J^π=23/2^-,T_1/2=160.4 days) target are described in this paper. Firstly, an isotopic separation of an enriched lutetium sample was used to reach a purity of ¹⁷⁶Lu close to 99.993%. Afterwards, the high neutron flux of the Grenoble Institut Laue-Langevin reactor was used to produce the ^177mLu isomer by the ¹⁷⁶Lu(n,γ) reaction. Finally, a chemical separation was performed to extract 10¹³ nuclei of ^177mLu. Thanks to this experiment, we have been able to estimate the destruction cross-section of the ^177mLu

[en] In this work, we present a few spectroscopic results deduced from a multiparticle-multihole Gogny energy density functional. Both pairing correlations in the ground state and low-lying spectroscopy of a few tin isotopes are discussed. All the results have been obtained using the same D1S Gogny interaction in the one-body mean-field and the residual part associated with a two-body and density-dependent Hamiltonian.

No abstract available

[en] An island of isomers have recently been observed on both sides of the N=40 shell below the Ni isotopes. Isomeric states in the 65Fe and 67Fe allow the knowledge of the single particle structure around the g9/2 shell. Moreover, the excitation energy of the first 2+ and 4+ states in the 68Fe have been established by β-γ correlation. The evolution of the structure of the Fe isotopes going far away from the valley of stability is, for the first time, given for N>40

No abstract available

[en] The inelastic neutron acceleration cross section on the long-lived metastable state of ¹⁷⁷Lu has been measured using a direct method. High-energy neutrons have been detected using a specially designed setup placed on a cold neutron beam extracted from the ORPHEE reactor in Saclay. The 146±19 b inelastic neutron acceleration cross section in the ORPHEE cold neutron flux confirms the high cross section for this process on the ¹⁷⁷Lu^m isomer. The deviation from the 258±58 b previously published obtained for a Maxwellian neutron flux at a 323 K temperature could be explained by the presence of a low energy resonance. Resonance parameters are deduced and discussed.

[en] Isomeric ratios and the momentum distributions of nuclei produced in the fragmentation of a 60AMeV ⁹²Mo beam on a thin ²⁷Al target have been studied. A strong dependence of the isomeric ratio on the structure of the isomer and on the reaction mechanism has been observed for the first time at intermediate energies

[en] A decay spectroscopic study of the neutron-rich isotopes has been performed using fragmentation of a ⁸⁶Kr primary beam. Fragments from this reaction have been selected by the LISE2000 spectrometer at the Grand Accelerateur National d'Ions Lourds (GANIL). Half-lives of 29 isotopes, including the first ones identified for ⁶¹Ti (15±4 ms), ⁶⁴V (19±8 ms), and ⁷¹Fe (28±5 ms), have been determined and compared with model predictions. ^67,68Mn β-delayed γ rays were observed for the first time. The branching for the β-delayed neutron emission was measured to be greater than 10(5)% in the ⁶⁷Mn decay. The ⁶⁷Fe isomeric level is firmly determined at higher energy than assigned in previous works. The excitation energies of the first (2⁺) and (4⁺) states of ⁶⁸Fe are suggested to lie at 522(1) and 1389(1) keV, respectively, thus bringing confirmation of assignments based on in-beam γ-ray spectroscopy. Beyond-mean-field calculations with the Gogny D1S force have been performed for even-mass nuclei through the Fe isotopic chain. Not only ⁶⁸Fe but most of the neutron-rich Fe isotopes with neutron numbers below N=50 are interpreted as soft rotors. The calculated mean occupancy of the neutron g_9/2 and d_5/2 orbitals in correlated ground states is steadily growing with increasing neutron number throughout the isotopic chain. Interpretation of ⁶⁷Fe data is based upon the present calculations for the ⁶⁶Fe and ⁶⁸Fe even cores.

[en] Thermal neutron radiative capture and burn-up measurements of the K isomeric state in 177Lu form part of an original method to indirectly obtain the neutron super-elastic scattering cross section at thermal energy. Neutron super-elastic scattering, also called neutron inelastic acceleration, occurs during the neutron collisions with an excited nuclear level. In this reaction, the nucleus could partly transfer its excitation energy to the scattered neutron