PAULO DE TARSO DALLEDONE SIQUEIRA
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Artigo IPEN-doc 27255 Neutron radiation effects on an electronic system on module2020 - LO PRESTI, DOMENICO; MEDINA, NILBERTO H.; GUAZZELLI, MARCILEI A.; MORALLES, MAURICIO; AGUIAR, VITOR A.P.; OLIVEIRA, JOSE R.B.; ADDED, NEMITALA; MACCHIONE, EDUARDO L.A.; SIQUEIRA, PAULO de T.D.; ZAHN, GUILHERME; GENEZINI, FREDERICO; BONANNO, DANILO; GALLO, GIUSEPPE; RUSSO, SALVATORE; SGOUROS, ONOUFRIOS; MUOIO, ANNAMARIA; PANDOLA, LUCIANO; CAPPUZZELLO, FRANCESCOThe NUMEN (NUclear Matrix Elements for Neutrinoless double beta decay) project was recently proposed with the aim to investigate the nuclear response to Double Charge Exchange reactions for all the isotopes explored by present and future studies of 0νββ decay. The expected level of radiation in the NUMEN experiment imposes severe limitations on the average lifetime of the electronic devices. During the experiments, it is expected that the electronic devices will be exposed to about 105 neutrons/cm2/s according to FLUKA simulations. This paper investigates the reliability of a System On Module (SOM) under neutron radiation. The tests were performed using thermal, epithermal, and fast neutrons produced by the Instituto de Pesquisas Energéticas e Nucleares 4.5MWNuclear Research Reactor. The results show that the National Instruments SOM is robust to neutron radiation for the proposed applications in the NUMEN project.Capítulo IPEN-doc 10982 Critical loading configurations of the IPEN/MB-01 reactor with a central cruciform rod2005 - SANTOS, A.; ANDRADE e SILVA, G.S.; FANARO, L.C.C.B.; YAMAGUCHI, M.; JEREZ, R.; ABE, A.Y.; FUGA, R.; SIQUEIRA, P.T.D.Artigo IPEN-doc 08664 Comparative in vivo and in vitro study of the cytogenetic effects of sup(153)Sm-EDTMP in lymphocytes of patients with bone metastases2002 - SILVA, M.A.; SUZUKI, M.F.; GUIMARAES, M.I.C.C.; BUCHPIGUEL, C.A.; ROGERO, J.R.; YORIYAZ, H.; SIQUEIRA, P.T.D.; COELHO, P.R.P.; OKAZAKI, K.Artigo IPEN-doc 14652 Physical models, cross sections, and numerical approximations used in MCNP and GEANT4 Monte Carlo codes for photon and electron absorbed fraction calculation2009 - YORIYAZ, HELIO; MORALLES, MAURICIO; SIQUEIRA, PAULO de T.D.; GUIMARAES, CARLA da C.; CINTRA, FELIPE B.; SANTOS, ADIMIR dosPurpose: Radiopharmaceutical applications in nuclear medicine require a detailed dosimetry estimate of the radiation energy delivered to the human tissues. Over the past years, several publications addressed the problem of internal dose estimate in volumes of several sizes considering photon and electron sources. Most of them used Monte Carlo radiation transport codes. Despite the widespread use of these codes due to the variety of resources and potentials they offered to carry out dose calculations, several aspects like physical models, cross sections, and numerical approximations used in the simulations still remain an object of study. Accurate dose estimate depends on the correct selection of a set of simulation options that should be carefully chosen. This article presents an analysis of several simulation options provided by two of the most used codes worldwide:MCNP and GEANT4. Methods: For this purpose, comparisons of absorbed fraction estimates obtained with different physical models, cross sections, and numerical approximations are presented for spheres of several sizes and composed as five different biological tissues. Results: Considerable discrepancies have been found in some cases not only between the different codes but also between different cross sections and algorithms in the same code. Maximum differences found between the two codes are 5.0% and 10%, respectively, for photons and electrons. Conclusion: Even for simple problems as spheres and uniform radiation sources, the set of parameters chosen by any Monte Carlo code significantly affects the final results of a simulation, demonstrating the importance of the correct choice of parameters in the simulation.