FRANCISCO DE ASSIS SOUZA

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Agora exibindo 1 - 5 de 5
  • Artigo IPEN-doc 29506
    Development of a fast simulator for GEM-based neutron detectors
    2022 - SANTOS, R.F. dos; MUNHOZ, M.G.; MORALLES, M.; SERRA FILHO, L.A.; BREGANT, M.; SOUZA, F.A.
    Gas Electron Multiplier (GEM)-based detectors using a layer of 10B as a neutron converter is becoming popular for thermal neutron detection. A common strategy to simulate this kind of detector is based on two frameworks: Geant4 and Gar eld++. The rst one provides the simulation of the nuclear interaction between neutrons and the 10B layer, while the second allows the simulation of the interaction of the reaction products with the detector gas leading to the ionization and excitation of the gas molecules. Given the high ionizing power of these nuclear reaction products, a full simulation is very time consuming and must be optimized to become viable. In this work, we present a strategy to develop a fast simulator based on these two frameworks that will allow us to generate enough data for a proper evaluation of the expected performance and optimization of this kind of detector. We will show the rst results obtained with this tool concentrating on its validation and performance.
  • Artigo IPEN-doc 29060
    Double-GEM based thermal neutron detector prototype
    2022 - SERRA FILHO, L.A.; FELIX DOS SANTOS, R.; SOUZA, G.G.A. de; PAULINO, M.M.M.; SOUZA, F.A.; MORALLES, M.; LUZ, H.N. da; BREGANT, M.; MUNHOZ, M.G.; LAI, C.-C.; HOGLUND, C.; SVENSSON, P.-O.; ROBINSON, L.; HALL-WILTON, R.
    The Helium-3 shortage and the growing interest in neutron science constitute a driving factor in developing new neutron detection technologies. In this work, we report the development of a double-GEM detector prototype that uses a 10B4C layer as a neutron converter material. GEANT4 simulations were performed predicting an efficiency of (3.14 ± 0.10)%, agreeing within 2.7σ with the experimental and analytic detection efficiencies obtained by the detector when tested in a 41.8 meV thermal neutron beam. The detector is position sensitive, equipped with a 256+256 strip readout connected to resistive chains, and achieves a spatial resolution better than 3 mm. The gain stability over time was also measured with a fluctuation of about 0.2% h-1 of the signal amplitude. A simple data acquisition with only 5 electronic channels is sufficient to operate this detector.
  • Capítulo IPEN-doc 28712
    Desenvolvimento de detectores de nêutrons sensível à posição
    2022 - SERRA FILHO, L.A.; SOUZA, F.A.; MORALLES, M.; LUZ, H.N. da; BREGANT, M.; MUNHOZ, M.G.
    O Instituto de Pesquisas Energéticas e Nucleares (IPEN) possui atualmente o maior reator de pesquisas nacional (IEA-R1), com algumas linhas de feixes de nêutrons disponíveis tanto para a inserção de novos instrumentos como para utilização desses feixes na caracterização e testes de detectores. Desde 2015 vem sendo desenvolvido, por meio de uma colaboração entre o IPEN e o Centro de Instrumentação e Física de Altas Energias (HEPIC) do Instituto de Física da Universidade de São Paulo (IF-USP), um protótipo de detector de nêutrons térmicos sensível à posição baseado em sistema de microestruturas multiplicadoras de elétrons em gás (GEM). Os experimentos têm sido realizados utilizando o feixe monocromático do difratômetro de nêutrons AURORA instalado no saguão experimental do reator IEA-R1.
  • Artigo IPEN-doc 28300
    Performance and optimization of a GEM-based neutron detector using a parameterized fast simulator
    2021 - SANTOS, R.F. dos; SERRA FILHO, L.A.; MUNHOZ., M.G.; BREGANT, M.; MORALLES, M.; SOUZA, F.A.
  • Artigo IPEN-doc 28228
    GEM-based thermal neutron detector prototype using boron-carbide converter
    2021 - SERRA FILHO, L.A.; SANTOS, R.F. dos; BREGANT, M.; MUNHOZ, M.G.; SOUZA, F.A.; MORALLES, M.; LUZ, H.N. da