FRANCISCO DE ASSIS SOUZA

FRANCISCO DE ASSIS SOUZA

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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.
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.
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.
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
Characterization of multilayer Thick-GEM geometries as 10B converters aiming thermal neutron detection
2018 - LUZ, H.N. da; SOUZA, F.A.; MORALLES, M.; CARLIN, N.; OLIVEIRA, R.A.N.; BREGANT, M.; SUAIDE, A.A.P.; CHUBACI, J.F.D.; MATSUOKA, M.; SILVA, T.F.; MORO, M.V.; RODRIGUES, C.L.; MUNHOZ, M.G.
Boron-based thermal neutron detectors have recently regained some attention from the instrumentation community as a strong alternative to helium-3 detectors. From the existing concepts exploiting boron layers in position sensitive detectors, the Cascade [1] is the one that takes full advantage of the 2D capabilities of gaseous detectors, with the position resolution not limited by the architecture of the detector. In this work, a proposal for the Cascade detector, based on Thick-GEMs is presented, together with some preliminary studies of the suitable pitch that optimizes the neutron conversion efficiency, while keeping the collection efficiency intact. The characterization of Thick-GEM prototypes produced in Brazil with hole pitch from 0.75 to 3 mm shows that these devices already present a stable performance at low gains, also resulting in fair energy resolution, when cascaded with a standard KaptonTM 50 µm GEM. Results of the first attempts of boron film depositions with Ion Beam Assisted Deposition and characterization by Ion Beam Analysis are also presented.
Towards position sensitive thermal neutron detection based in multilayer 10B converters
2017 - LUZ, H.N. da; SOUZA, F.A.; SERRA FILHO, L.A.; MORALLES, M.; BREGANT, M.; CARLIN, N.; HOGLUND, C.; MUNHOZ, M.G.; SCHMIDT, S.; SUAIDE, A.A.P.; SVENSSON, P.O.
One of the most relevant issues in neutron detection is the search for alternatives to 3He as neutron converter. Its high absorption cross section for thermal neutrons used to make it the preferred absorber to build large area thermal neutron detectors. Its current unavailability triggered an intense search to find alternatives like gaseous detectors coated with 10B for neutron conversion. Such element is found in the solid state at NPT presenting an additional challenge regarding its deposition on surfaces with an optimum thickness. This is a critical parameter of the detector, since issues such as the self-absorption of the products of the nuclear reaction when the films are too thick can limit the detection efficiency of the final detector. The use of many layers is an interesting solution to overcome these issues. This has been tried in several geometries, such as Multi-grid, Inclined detector, Jalousie and Cascade. In this presentation, a solution based in the Cascade concept where several thin boron layers are used, will be presented, using a cost effective Micropattern Gaseous Detector, the Thick-Gas Electron Multiplier (Thick-GEM), as neutron converter and electron transporter, together with a standard GEM-based charge amplification stage. Preliminary results obtained with a first prototype mounted at IPEN’s research reactor, using 10B4C neutron converters produced in the deposition lab of the European Spallation Source will be shown and further developments towards position sensitive detection both for beam monitors and for high efficiency neutron detectors will be discussed.
Future perspectives for neutron beam utilization in Brasil
2014 - PERROTTA, J.A.; SOARES, A.J.; GENEZINI, F.A.; SOUZA, F.A.; FRANCO, M.K.K.D.; GRANADO, E.
New measurement of the B-11(p,alpha(0))Be-8 bare-nucleus S(E) factor via the Trojan horse method
2012 - LAMIA, L.; SPITALERI, C.; BURJAN, V.; CARLIN, N.; CHERUBINI, S; CRUCILLA, V; GAMEIRO MUNHOZ, M.; GIMENEZ DEL SANTO, M.; GULINO, M.; HONS, Z.; KISS, G.G.; KROHA, V.; KUBONO, S.; LA COGNATA, M.; LI, C.; MRAZEK, J.; MUKHAMEDZHANOV, A.; PIZZONE, R.G.; PUGLIA, S.M.R.; WEN, Q.; RAPISARDA, G.G.; ROLFS, C.; ROMANO, S.; SERGI, M. L.; SOMORJAI, E.; SOUZA, F.A.; SZANTO de TOLEDO, A.; TABACARU, G.; TUMINO, A.; WAKABAYASHI, Y.; YAMAGUCHI, H.; ZHOU, S-H