Possibilités d'accroissement de la productivité économique du zébu malgache par amélioration génétique et alimentation intensive

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Fission in inverse kinematics

Fission is a unique tool to study nuclear properties. The SOFIA Collaboration takes advantage of the inverse kinematics technique to measure fission yields for a large range of systems, including exotic nuclei. Both fragments are fully identified in charge and mass, a unique feature. The use of Coulomb interaction as fission trigger results in a low excitation energy in the fissioning system, allowing to study the influence of nuclear structure on fission. Using samples of SOFIA results, this paper addresses some open questions about fission such as the evolution of elemental yields with mass and the transition between asymmetric and symmetric fission

Energy measurement of prompt fission neutrons in 239Pu(n,f) for incident neutron energies from 1 to 200 MeV

Prompt fission neutron spectra in the neutron-induced fission of 239Pu have been measured for incident neutron energies from 1 to 200 MeV at the Los Alamos Neutron Science Center. Preliminary results are discussed and compared to theoretical model calculation

New states in 18Na and 19Mg observed in the two-proton decay of 19Mg

Previously unknown states in 18Na and 19Mg have been studied by measuring the trajectories of their decay products with microstrip detectors. Analyzing angular correlations of the fragments provided information on decay energies and widths of the parent states. The ground state of 18Na has been detected and its one-proton decay energy of 1.23(15) MeV determined. Four previously unknown states in 19Mg at 2.1, 2.9, 3.6, and 5.2 MeV have been observed. The competition between simultaneous and sequential two-proton emission of states in 19Mg is discussed, and the conclusion of a direct mechanism of 2p radioactivity of the 19Mg ground state is confirmed.MEC EC-I3 FPA2006-13807-C02-01Ministerio de Economía y Competitividad FPA2009-0884

Coulomb excitation of exotic nuclei at the R3B-LAND setup

Exotic Ni isotopes have been measured at the R3B-LAND setup at GSI in Darmstadt, using Coulomb excitation in inverse kinematics at beam energies around 500 MeV/u. As the experimental setup allows kinematically complete measurements, the excitation energy was reconstructed using the invariant mass method. The GDR and additional low-lying strength have been observed in 68Ni, the latter exhausting 4.1(1.9)% of the E1 energy-weighted sum rule. Also, the branching ratio for the non-statistical decay of the excited 68Ni nuclei was measured and amounts to 24(4)%.Comment: 11 pages, 7 figures. Invited Talk given at the 11th International Conference on Nucleus-Nucleus Collisions (NN2012), San Antonio, Texas, USA, May 27-June 1, 2012. To appear in the NN2012 Proceedings in Journal of Physics: Conference Series (JPCS