Micromegas (Micro-MEsh Gaseous Structure) detectors are gas detectors consisting of a stack of one ionization and one proportional chamber. A micromesh separates the two communicating regions, where ...two different electric fields establish respectively a charge drift and a charge multiplication regime. The n_TOF facility at CERN provides a white neutron beam (from thermal up to GeV neutrons) for neutron induced cross section measurements. These measurements need a perfect knowlodge of the incident neutron beam, in particular regarding its spatial profile. A position sensitive micromegas detector equipped with a 10B based neutron/charged particle converter has been extensively used at the n_TOF facility for characterizing the neutron beam profile and extracting the beam interception factor for samples of different size. The boron converter allowed to scan the energy region of interest for neutron induced capture reactions as a function of the neutron energy, determined by the time of flight. Experimental results will be presented and compared to simulations, performed by means of the FLUKA code.
We have used the 4π BaF2 gamma-ray detector array at the n_TOF neutron time-of-flight facility at CERN for an experiment in order to determine the spins of resonances of n +87Sr by measuring the ...gamma-ray spectra and multiplicity distributions. The first results are presented here. We have assigned the orbital momentum ℓ to all evaluated resonances on the basis of their neutron widths. Further we have assigned the spin J to 16 s-wave resonances on based the population of low-lying levels.
The capture cross sections of 241Am and 243Am were measured at the n_TOF facility at CERN in the epithermal energy range with a BaF2 Total Absorption Calorimeter. A preliminary analysis of the 241Am ...and a complete analysis of the 243Am measurement, including the data reduction and the resonance analysis, have been performed.
The (n, α) reaction in the radioactive 59Ni is of relevance in nuclear astrophysics as 59Ni can be considered as the first branching point in the astrophysical s-process. Its relevance in nuclear ...technology is especially related to material embrittlement in stainless steel. However, there is a discrepancy between available experimental data and the evaluated nuclear data files for this reaction. At the n_TOF facility at CERN, a dedicated system based on sCVD diamond diodes was set up to measure the 59Ni(n, α)56Fe cross section. The results of this measurement, with special emphasis on the dominant resonance at 203 eV, are presented here.
The accurate knowledge of relevant nuclear data is crucial for the design of advanced nuclear systems. These data include neutron cross sections of various plutonium isotopes and other minor ...actinides. The 242Pu(n,f) cross section was measured at the CERN n_TOF facility, taking advantage of the wide energy range (from thermal to GeV) and the high instantaneous flux of the neutron beam. Preliminary results for the measurement are presented.
Neutron induced capture cross section on 236U has been measured with high accuracy and high resolution at n_TOF, in order to improve data libraries needed for the development of advanced nuclear ...reactors. Preliminary results obtained with two different detection systems are reported.
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