VITOR VIVOLO
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Artigo IPEN-doc 23025 Mass attenuation coefficients of X-rays in different barite concrete used in radiation protection as shielding against ionizing radiation2017 - ALMEIDA JUNIOR, T.A.; NOGUEIRA, M.S.; VIVOLO, V.; POTIENS, M.P.A.; CAMPOS, L.L.The probability of a photon interacting in a particular way with a given material, per unit path length, is usually called the linear attenuation coefficient (μ), and it is of great importance in radiation shielding. Plates of barite concrete with different thickness were fabricated in order to determining their mass attenuation coefficients at different energies. The plates were irradiated with ISO X-ray beams (N60, N80, N110 and N150), generated by Pantak HF320 X-ray equipment, at the IPEN laboratory. The mass attenuation coefficients of barite concrete have been measured using X-ray attenuation for different thicknesses of barite concrete qualities of the ISO. The attenuator material issued from different regions of Brazil. The experimental procedure in this research was validated by comparison between the experimental measurements of mass attenuation coefficients and coefficients determined by the same atomic composition, using as a tool to XCOM. The highest value of (μ/ ρ) found experimentally was in the energy of 48 keV, in ISO 60 N quality, being 1.32( ± 0.49) for purple barite; 1.47( ± 0.41) for white barite and 1.75( ± 0.41) for cream barite. The determination of the chemical composition of the barite samples was of fundamental importance for the characterization of these materials. It can be seen that both calculated and measured data for the linear attenuation coefficients increase with the increasing materials density, as it is expected. It can be concluded that the photon attenuation coefficients depends on the photon energy and the materials density is the main contribution to the photon attenuation coefficients, which is important for radiation shielding.Artigo IPEN-doc 20883 Response and Monte Carlo evaluation of a reference ionization chamber for radioprotection level at calibration laboratories2015 - NEVES, LUCIO P.; VIVOLO, VITOR; PERINI, ANA P.; CALDAS, LINDA V.E.Artigo IPEN-doc 20258 Evaluation of epitaxial silicon diodes as dosimeters in X-ray mammography2014 - GONCALVES, J.A.C.; PEREIRA, L.N.; POTIENS, M.P.A.; VIVOLO, V.; BUENO, C.C.Artigo IPEN-doc 20030 Intensity variation study of the radiation field in a mammographic system using thermoluminescent dosimeters TLD-900 (CaSOsub(4):DY)2014 - CORREA, E.L.; SILVA, J.O.; VIVOLO, V.; POTIENS, M.P.A.; DAROS, K.A.C.; MEDEIROS, R.B.Artigo IPEN-doc 19573 Quality control tests in a mammographic unit using a homemade ionization chamber2013 - SILVA, JONAS O.; CORREA, EDUARDO I.; VIVOLO, VITOR; POTIENS, MARIA da P.A.; CALDAS, LINDA V.E.An important modality of radiation diagnosis is the mammography that is a diagnostic tool to detect breast cancer in an initial stage as well as the tumor localization for treatment. It is essential that the mammographic unit follows an accurate quality control program to assure the image quality, and patient and staff radiation protection. The ionization chambers play an important role in the quality control of mammographic units, because they are the reference detectors for calibration purposes. In this work a homemade double faced ionization chamber developed at IPEN, Brazil, was used to perform some quality control tests in a mammographic unit. All results obtained were within international recommendations.Artigo IPEN-doc 18278 Quality control methodology and implementation of X-radiation standards beams, mammography level, following the standard IEC 612672012 - CORREA, E.L.; VIVOLO, V.; POTIENS, M.P.A.Artigo IPEN-doc 14491 Preliminary studies of a new monitor ionization chamber2010 - YOSHIZUMI, MAIRA T.; VIVOLO, VITOR; CALDAS, LINDA V.E.Artigo IPEN-doc 14493 Characteristics of a tandem system of ionization chambers in x-ray beams mammography level2010 - AFONSO, L.C.; VIVOLO, VITOR; CALDAS, L.V.E.Artigo IPEN-doc 16666 Evaluation of the planar sources surface homogeneity used to instruments calibration2010 - VIVOLO, VITOR; POTIENS, MARIA da P.A.Artigo IPEN-doc 18288 Evaluation of the voltage quantities measured with different noninvasive meter for quality control at a calibration laboratory2012 - VIVOLO, VITOR; NEVES, LUCIO P.; PERINI, ANA P.; SILVA, JONAS O.; LUCENA, RODRIGO F.; POTIENS, MARIA da P.A.; CALDAS, LINDA V.E.