JONAS OLIVEIRA DA SILVA
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Artigo IPEN-doc 24422 Performance tests of a special ionization chamber for X-rays in mammography energy range2017 - SILVA, J.O.; CALDAS, L.V.E.A special mammography homemade ionization chamber was developed to be applied for mammography energy range dosimetry. This chamber has a total sensitive volume of 6 cm3 and is made of a PMMA body and graphite coated collecting electrode. Performance tests as saturation, ion collection efficiency, linearity of chamber response versus air kerma rate and energy dependence were determined. The results obtained with this special homemade ionization chamber are within the limits stated in international recommendations. This chamber can be used in quality control programs of mammography energy range. All measurements were carried out at the Calibration Laboratory of IPEN.Artigo IPEN-doc 23961 Assessment of dosimetric parameters in mammography employing a homemade ionization chamber2016 - SILVA, J.O.; CALDAS, L.V.E.X-ray mammography examination is the reference tool to discover breast cancer in an early stage. The mammography unit must follow an accurate quality control program that covers both patient and staff radiation protection. Plane parallel ionization chambers are the reference instrument for dosimetry in mammography beams, but they can represent higher cost for small clinics in countries as Brazil. In this work, it is presented a low cost ionization chamber for mammography X-rays energy range dosimetry developed at IPEN. The homemade ionization chamber has a sensitive volume of 6.0 cm3 and it was utilized to execute quality control tests in two distinct mammography systems: a GE Senographe DMR-plus and a Philips VMI Graph Mammo. The setups for the tests performed agreed with the IAEA HHS 2 and 17 recommendations. A breast phantom of various PMMA thicknesses was utilized in this work. The homemade ionization chamber performance was compared to that of a commercial one. The maximum difference between the incident air kerma measured with the reference ionization chamber and the developed one was only 5.62% for the GE equipment and only 4.42% for the Philips equipment. The homemade ionization chamber presented an excellent performance in incident air kerma and HVL measurements for the radiographic techniques utilized in the present work. All the results obtained were within IAEA specifications.Artigo IPEN-doc 21016 Characterization tests and application of special ionization chambers in standard mammography beams2015 - HONDA, CRISTIANE J.C.; SILVA, JONAS O.; CALDAS, LINDA V.E.Resumo IPEN-doc 17648 Aplicação de um sistema tandem de câmaras de ionização em feixes padronizados de mamografia2011 - SILVA, JONAS O. da; CALDAS, LINDA V.E.Resumo IPEN-doc 15987 A tandem system for quality control in mammography beams2010 - SILVA, J.O.; CALDAS, L.V.E.Resumo IPEN-doc 18631 Characterization tests of a homemade ionization chamber in mammography standard radiation beams2012 - SILVA, J.O.; NONATO, F.B.C.; CALDAS, L.V.E.Artigo IPEN-doc 18744 Stability study of ionization chambers in standard mammography radiation beams2012 - SILVA, JONAS O. da; CALDAS, LINDA V.E.Artigo IPEN-doc 18531 Quality control tests in a mammographic unit using a homemade ionization chamber2012 - SILVA, JONAS O.; CORREA, EDUARDO L.; VIVOLO, VITOR; POTIENS, MARIA da P.A.; CALDAS, LINDA V.E.Artigo IPEN-doc 18568 Comparing the stability of two ionization chambers in standard mammography radiation beams and using an Sr-90+Y-90 check device2012 - SILVA, J.O.; CALDAS, L.V.E.Artigo IPEN-doc 17503 Establishment of a tandem ionization chamber system in standard mammography beams2011 - SILVA, JONAS O. da; CALDAS, LINDA V.E.