PAULO DE TARSO DALLEDONE SIQUEIRA
3 resultados
Resultados de Busca
Agora exibindo 1 - 3 de 3
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 30620 Study of the behavior of 3 MeV proton beams on PMMA2024 - PEREIRA, J.; MATIAS, F.; ANTUNES, P.; SHORTO, J.; SIQUEIRA, P.; SILVA, T.; RODRIGUES, C.; OTUBO, L.; FERREIRA, G.; YORIYAZ, H.Artigo IPEN-doc 30433 Efficient computational modeling of electronic stopping power of organic polymers for proton therapy optimization2024 - MATIAS, F.; SILVA, T.F.; KOVAL, N.E.; PEREIRA, J.J.N.; ANTUNES, P.C.G.; SIQUEIRA, P.T.D.; TABACNIKS, M.H.; YORIYAZ, H.; SHORTO, J.M.B.; GRANDE, P.L.This comprehensive study delves into the intricate interplay between protons and organic polymers, offering insights into proton therapy in cancer treatment. Focusing on the influence of the spatial electron density distribution on stopping power estimates, we employed real-time time-dependent density functional theory coupled with the Penn method. Surprisingly, the assumption of electron density homogeneity in polymers is fundamentally flawed, resulting in an overestimation of stopping power values at energies below 2 MeV. Moreover, the Bragg rule application in specific compounds exhibited significant deviations from experimental data around the stopping maximum, challenging established norms.