PAULO DE TARSO DALLEDONE SIQUEIRA
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Artigo IPEN-doc 31167 Development of a sample exchange system for irradiations in the BH-3 channel of the IEA-R1 reactor at IPEN2024 - PAULA, M.L. de; MORALLES, M.; GENEZINI, F.A.; SIQUEIRA, P.T.D.; RIBEIRO JUNIOR, I.S.; SILVA JUNIOR, I.A. daThis work was developed with the aim of improving the current sample exchange system of the BH-3 irradiation channel of the IEA-R1 reactor at IPEN. The instrument's operating concept will provide a better use of the irradiation space as well as greater safety and confidence to the operator. The development of the system involved 3D modeling, sizing, construction and non-destructive testing of the various parts, and analysis of neutron-induced activation of the materials most exposed to the beam. A programmable logic controller (PLC) was implemented for the system’s control inside a dedicated electrical panel that was built with materials compatible with the location. The system was designed to support samples weighing up to 15 kg. Bench tests were carried out and showed that the system performs the necessary functions to accurately position samples in three locations: outside the biological shield, at the irradiation channel and at the decay waiting station. The implementation of this instrument will contribute to the application of the ALARA principle in the operator activities at the BH-3 irradiation channel.Artigo IPEN-doc 25846 Verification of angular dependence in MOSFET detector2019 - SOUZA, C.H.; SHORTO, J.M.B.; SIQUEIRA, P.T.D.; NUNES, M.G.; SILVA JUNIOR, I.A.; YORIYAZ, H.In vivo dosimetry is an essential tool for quality assurance programs, being a procedure commonly performed with thermoluminescent dosimeters (TLDs) or diodes. However, a type of dosimeter that has increasing popularity in recent years is the metal-oxide-semiconductor field effect transistor (MOSFET) detector. MOSFET dosimeters fulfill all the necessary characteristics to realize in vivo dosimetry since it has a small size, good precision and feasibility of meas-urement, as well as easy handling. Nevertheless, its true differential is to allow reading of dose in real time, enabling immediate intervention in the correction of physical parameters deviations and anticipation of small anatomical changes in the patient during treatment. In order for MOSFET dosimeter to be better accepted in clinical routine, information reporting performance should be available frequently. For this reason, this work proposes to verify reproducibility and angular dependence of a standard sensitivity MOSFET dosimeter (TN-502RD-H) for Cs-137 and Co-60 sources. Exper-imental data were satisfactory and MOSFET dosimeter presented a reproducibility of 3.3% and 2.7% (±1 SD) for Cs-137 and Co-60 sources, respectively. In addition, an angular dependence of up to 6.1% and 16.3% for both radioactive sources, respectively. It is conclusive that MOSFET dosimeter TN-502RD-H has satisfactory reproducibility and a considerable angular dependence, mainly for the Co-60 source. This means that although precise measurements, special attention must be taken for applications in certain anatomical regions in a patient.Artigo IPEN-doc 24419 Comparação entre duas metodologias para correção da uniformidade de fontes extensas de referência2017 - SILVA JUNIOR, I.A.; SIQUEIRA, P.T.D.; NASCIMENTO, E.; VIVOLO, V.; POTIENS, M.P.A.São apresentados neste artigo os procedimentos para obtenção de fatores de correção de uniformidade de fontes ex- tensas de referência sugerida por duas metodologias distintas. A primeira metodologia é apresentada pelo Guia de Boas Práticas do Nº 14 do NPL, que oferece uma correção numérica e a segunda é uma correção que utiliza o código de transporte de radiação, MCNP5. Ambos os métodos resultam na proposição de valores de correções muito simila- res percentualmente, com desvio máximo de 0,24%.