FRANCISCO DE ASSIS SOUZA
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Artigo IPEN-doc 25212 Characterization of multilayer Thick-GEM geometries as 10B converters aiming thermal neutron detection2018 - 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.Resumo IPEN-doc 24527 Towards position sensitive thermal neutron detection based in multilayer 10B converters2017 - 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.Artigo IPEN-doc 20723 Future perspectives for neutron beam utilization in Brasil2014 - PERROTTA, J.A.; SOARES, A.J.; GENEZINI, F.A.; SOUZA, F.A.; FRANCO, M.K.K.D.; GRANADO, E.Artigo IPEN-doc 18051 New measurement of the B-11(p,alpha(0))Be-8 bare-nucleus S(E) factor via the Trojan horse method2012 - 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