PAULO DE TARSO DALLEDONE SIQUEIRA

PAULO DE TARSO DALLEDONE SIQUEIRA

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Neutron radiation effects on an electronic system on module
2020 - 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, FRANCESCO
The 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.
Variability
2020 - SILVA JÚNIOR, IREMAR A. da; SIQUEIRA, PAULO de T.D.; NASCIMENTO, EDUARDO do; YORIYAZ, HELIO; SORDI, GIAN-MARIA A.A.; POTIENS, MARIA da P.A.
In this paper we present the impact of variability, a surface source parameter, on the efficiency evaluation of surface contamination monitors. This study was based on two source uniformity correction methodologies and data from real surface source distributions. Surface source intensity distribution has been changed by rearranging the cells (portions of the active area of each LARS) while keeping the same source uniformity value. Instrument efficiencies have been calculated for different sets of uniformities and variabilities. This study led to emphasize the importance of variability, a differential source intensity distribution parameter, over the uniformity, an integral source intensity distribution parameter, and reinforced the importance of the source uniformity correction procedure on the course of surface contamination monitor calibration.
Correction factors for non-uniform large-area reference sources
2020 - SILVA JÚNIOR, IREMAR A.; SIQUEIRA, PAULO de T.D.; NASCIMENTO, EDUARDO do; YORIYAZ, HELIO; SORDI, GIAN-MARIA A.A.; VIVOLO, VITOR; POTIENS, MARIA da P.A.
Based on uniformity measurements of large-area reference sources used in calibration procedures of surface contamination monitors, an investigation was carried out to obtain a method that estimates the bias originated from surface source intensity distribution deviation from the ideal uniform distribution and corrects it. It relies on correcting the estimated instrument efficiency by applying correction factors driven from the uniformity distribution profiles of the sources used in calibration procedure. Simulations of the monitor calibration procedure are run for 2 distinct surface source distributions: the real and the ideally uniform distributions. Correction factors are driven from counting rate estimates obtained from each source representation. In order to evaluate adequacy of this proposition it was validated against a method proposed by the NPL in the Good Practices Guide No.14.
Design, fabrication and modeling of an AmBe neutron irradiator for TLD screening for neutron dose measurement in mixed radiation fields
2019 - CAVALIERI, TASSIO A.; SIQUEIRA, PAULO T.D.; SHORTO, JULIAN M.B.; GENEZINI, FREDERICO A.; YORIYAZ, HELIO
TLDs dosimeters are frequently presented as a viable choice for dosimetric studies when dealing with mixed neutron-gamma radiation fields. However, this choice is not without some drawbacks, because not only TLD response is highly dependent on particle type but also on neutron energy spectrum. Therefore, a correct screening and calibration of the dosimeter are required, and a simple shift from gamma screening methodology for mixed field is not suitable. This paper presents the design, fabrication and tests of an irradiator for TLD screening for neutron dose measurement using an AmBe source and polyethylene as moderator material. The design of the irradiator was conducted through Monte Carlo simulations using the MCNP5 code. The experimental validation and tests were performed using Indium activation foils and TLD 600 dosimeters. The manufactured irradiator demonstrated to be suitable for TLD screening under neutron source radiation field, offering very good homogeneity conditions in the radiation field so to guarantee same radiation dose delivered to the TLDs.
Study of pixel damages in CCD cameras irradiated at the neutron tomography facility of IPEN-CNEN/SP
2015 - PUGLIESI, R.; ANDRADE, M.L.G.; DIAS, M.S.; SIQUEIRA, P.T.D.; PEREIRA, M.A.S.