Neutron single particle structure in Sn131 and direct neutron capture cross sections

Recent calculations suggest that the rate of neutron capture by Sn130 has a significant impact on late-time nucleosynthesis in the r process. Direct capture into low-lying bound states is expected to be significant in neutron capture near the N=82 closed shell, so r-process reaction rates may be strongly impacted by the properties of neutron single particle states in this region. In order to investigate these properties, the (d,p) reaction has been studied in inverse kinematics using a 630MeV beam of Sn130 (4.8MeV/u) and a (CD 2) n target. An array of Si strip detectors, including the Silicon Detector Array and an early implementation of the Oak Ridge Rutgers University Barrel Array, was used to detect reaction products. Results for the Sn130(d, p)Sn131 reaction are found to be very similar to those from the previously reported Sn132(d, p)Sn133 reaction. Direct-semidirect (n,γ) cross section calculations, based for the first time on experimental data, are presented. The uncertainties in these cross sections are thus reduced by orders of magnitude from previous estimates. © 2012 American Physical Society

One-neutron transfer study of 135Te and 137Xe by particle-γ coincidence spectroscopy: The ν1i13/2 state at N = 83

Additional information is reported on single-neutron states above the doubly closed-shell nucleus 132Sn. A radioactive ion beam of 134Te(N=82) at 565 MeV and a stable ion beam of 136Xe(N=82) at 560 MeV were used to study single-neutron states in the N=8

Levels above the 19/2- isomer in Cu71: Persistence of the N=40 neutron shell gap

Two prompt γ rays of energies 2020 and 554 keV were observed in coincidence with delayed transitions depopulating the 19/2- isomer in the Z=29, N=42 Cu71 nucleus. The newly identified transitions are proposed to deexcite the 4776- and 5330-keV levels above the 19/2- isomer. Based on the comparison with the low-lying positive-parity states observed in the Z=42, N=50 Mo92 nucleus, spin and parity 23/2- are proposed for the 4776-keV level in Cu71. The high-energy, 2020-keV transition is interpreted as arising from the breaking of the N=40 neutron core. Shell-model calculations with a Ni56 core reproduce the (23/2-)→(19/2-) gap well, suggesting that the 23/2- state is dominated by πp3/2ν((fp)10(g9/2)4) configurations. The present result constitutes further evidence supporting the view that the N=40 subshell closure persists in Cu71, herewith challenging recent suggestions that the coupling of two or more proton or neutron quasiparticles induces a large polarization of the Ni68 core

Overview of IFMIF-DONES diagnostics: Requirements and techniques

The IFMIF-DONES Facility is a unique first-class scientific infrastructure whose construction is foreseen in Granada, Spain, in the coming years. Strong integration efforts are being made at the current project phase aiming at harmonizing the ongoing design of the different and complex Systems of the facility. The consolidation of the Diagnostics and Instrumentation, transversal across many of them, is a key element of this purpose. A top-down strategy is proposed for a systematic Diagnostics Review and Requirement definition, putting emphasis in the one-of-a-kind instruments necessary by the operational particularities of some of the Systems, as well as to the harsh environment that they shall survive. In addition, other transversal aspects such as the ones related to Safety and Machine Protection and their respective requirements shall be also considered. The goal is therefore to advance further and solidly in the respective designs, identify problems in advance, and steer the Diagnostics development and validation campaigns that will be required. The present work provides an overview of this integration strategy as well as a description of some of the most challenging Diagnostics and Instruments within the facility, including several proposed techniques currently under study

High spin states in neutron rich Ni isotopes

The neutron rich Ni isotopes have been studied using the quasi and deep inelastic reactions in 64Ni bombardments of the thick 208Pb target at 350 MeV. The amp; 947; amp; 947; coincidence analysis and half life measurements provided new spectroscopic information for heavy, A 64 to 67 Ni isotopes with particular emphasis on the high spin states and the role of the g9 2 neutron orbita

Neutron and proton flow between the colliding 208Pb and 64Ni ions

The 208Pb 64Ni reaction at 350 MeV energy was investigated using amp; 947; amp; 947; coincidence technique and target radioactivity measurements. The determined distribution of products indicates a dominant role of deep inelastic collisions. The flow of protons and neutrons between the colliding nuclei is discussed in terms of mass and charge equilibration processe

Gamma decay of the particle hole states with the highest spins in 208Pb

208Pb has been excited with inelastic heavy ion scattering of 350 MeV64Ni and 420 MeV82Se on a thick208Pb target. With amp; 947; amp; 947; coincidence measurements 2 new decays of the 10 isomer, namely a 34.5 keVE2 transition to 8 2 and a 857.7 keVE3 transition to 7 amp; 8722; have been found and the wavefunctions of the participating levels deduced. An observed gamma cascade of 295.3, 348.0, 865.4 and 340.2 keV on top of the 10 isomer is assigned to the particle hole states with the highest spins 14 amp; 8722; 6744.1 keV amp; 8594;13 amp; 8722; 6448.9 keV amp; 8594;12 6100.9 keV amp; 8594;11 5235.6 keV amp; 8594;10 4895.4 ke