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The neutrons for science facility (NFS), the first operational experimental area of the new GANIL/SPIRAL-2 facility, received its first beams in December 2019. Proton-induced reaction cross-sections as well as neutron beam characteristics were measured during the first commissioning phases. The first results, showing the features of the facility, are presented here and compared with previously published data. The physics cases and the first accepted experiments are presented as well. [ABSTRACT FROM AUTHOR]

This study focuses on the oxidation behavior of commercially available HR120 in air at 1,050 °C from 30 min to 100 h. The oxidation kinetics were first studied by thermogravimetry and isothermal exposure. The oxidation products were fully characterized using ex and in situ X-ray diffraction (XRD) and FEG-SEM observations. HR120 experienced at 1,050 °C a non protective transient stage and formed a multilayered oxide scale (SiO-CrO-XCrO with X = Mn and/or Fe, Ni). A series of complementary characterization methods (gold and isotopic marker experiments, photoelectrochemistry (PEC)) were implemented to elucidate the oxidation mechanism. The study identified a n-type semi-conductivity accompanied by an inward growth of the scale. Thus, assuming that diffusion in the oxide scale controlled chromia-scale growth, the oxygen vacancy was the major point defect governing the solid state transport. This result was attributed to the presence of a MnCrO spinel layer at the top of chromia that strongly decreased the oxygen pressure at the interface spinel/chromia. [ABSTRACT FROM AUTHOR]

In this paper we present for the first time the measured delayed neutron (DN) yields and time spectra from high-energy protons interacting with thick natPb targets. The 1GeV protons from the accelerator impinged on targets of different thicknesses producing a huge number of spallation-fission products, some of which can be DN precursors. After the beam is switched off, the DNs were detected with optimized 3He counter. The production yields of light DN precursors as 17N and “usual” fission products as 87Br and 88Br, which dominate the total DN activity, are obtained both for thin and thick targets. These new data are of great interest for the new generation high-power spallation targets based on liquid-metal technologies. Our findings also should help to constrain the physics models within the simulations codes. [ABSTRACT FROM AUTHOR]

The creation of isomeric nuclei by neutron capture in the resonances energy range was studied with the lead slowing-down assembly CIRENE. The isomeric-ratio measurement of 8 nuclei allows to determine the spin of the compound nucleus at the binding energy. An experiment on 177Lu underlines the role of the spin of a resonance on the isomeric-state feeding probability. [ABSTRACT FROM AUTHOR]

Neutrons and light charged particles produced in 62.9MeV proton-induced reactions on208Pb were measured during a single experiment performed at the CYCLONE facility in Louvain-la-Neuve (Belgium). Two independent experimental set-ups were used to extract double differential cross-sections for neutrons, protons, deuterons, tritons,3He and alpha-particles. Charged particles were detected using a set of Si- Si- CsI telescopes from 25° to 155°, by step of 10 degrees. Neutrons were measured using shielded DeMoN counters, liquid NE213 scintillators, at 24°, 35°, 55°, 80° and 120°. These data allowed the determination of angle differential, energy differential and total production cross-sections. A comparison with theoretical calculations (MCNPX, FLUKA and TALYS) has been performed. It shows that the neutron and proton production rates are well predicted by MCNPX, using the INCL4 option. All the other codes underestimate the neutron production whereas they overestimate the proton one. For composite particles, which represent 17% of the charged particle total reaction cross-section, neither the shape nor the amplitude of the cross-sections are correctly predicted by the models. [ABSTRACT FROM AUTHOR]

Inclusive neutron energy spectra were measuredb y time of flight using 1.22 GeV antiprotons from LEAR, CERN, as projectiles andtargets from natural Al, Cu, Ag, Ho, Ta, Au, Pb, Bi, U. The sum of two Maxwellian distributions was fitted to the spectra d2 σ/(d Ωd E) obtainedat several forward andbac kwardangles yielding neutron multiplicities M i andslop e or temperature parameters T i for the low-energy (evaporative, i = 1) andhigh-energy (pre-equilibrium, i = 2) parts, respectively. M 1 increases with A, proportional to the nuclear volume, and M 2 is growing with A 1/3, proportional to the nuclear radius. The T parameters are nearly independent of A. The results are comparedwith previous multiplicity measurements with a 4 π neutron detector, intranuclear cascade calculations and neutron spectra from stoppedan tiproton annihilation on nuclei. With the measuredproton spectra also the ratio of emitted neutrons to protons was determined for Au. [ABSTRACT FROM AUTHOR]

Cross sections for stripping and dissociation of deuterons interacting with Be targets in the 100–2300 MeV energy range have been measured. Comparisons with model calculations suggest a dominant contribution of the stripping process. It is also shown that the deuteron break-up cross section exhibits the same energy dependence as the nucleon-nucleon cross section. [ABSTRACT FROM AUTHOR]