NATALIA FIORINI DA SILVA
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Artigo IPEN-doc 26788 Garfield++ simulation of a TH-GEM based detector for standard mammography beam dosimetry2019 - SILVA, N.F.; SILVA, T.F.; CASTRO, M.C.; LUZ, H.N. da; CALDAS, LINDA V.E.The TH-GEM based detector is a robust, simple to manufacture, high-gain gaseous electron multiplier. Its operation is based on a standard printed circuit board (PCB) coated on both sides by metallic material, perforated in a millimeter pattern, and immersed in gas. In order to study the feasibility of using TH-GEM type detectors in dosimetric applications for standard mammography beams, a prototype with adequate dimensions and materials was produced. The present work encompasses the calculations of electric fields by the Gmsh and Elmer software packages and the avalanche simulation using Garfield++ library of a TH-GEM detector filled with Ar/CO2 (70:30) mixture at atmospheric pressure.Artigo IPEN-doc 24056 Evaluation of the influence of the TH-GEM detector components in dosimetric measurements of standard mammography beams2017 - SILVA, NATALIA F.; SILVA, TIAGO F.; CASTRO, MAYSA C.; CINTRA, FELIPE B.; LUZ, HUGO N. da; CALDAS, LINDA V.E.GEM detectors have found applications in many areas due to their simplicity of construction, low cost, ruggedness and diversity of shape. A dosimeter with these qualities presents utility in several applications, as for example in diagnostic and therapeutic medicine, industrial radiography and nuclear meters. Furthermore, the high sensitivity provided by GEM detectors may extend their applications in low dose dosimetry. Based on these facts, it may be interesting to produce a prototype of a portable TH-GEM type detector with characteristics suitable for dosimetric use in X-rays with low and medium energies. The precise determination of the dosimeter characteristics is very important for laboratories of instrument calibration, as well as to determine how the various components of the detector may influence on the energy deposited in the sensitive volume. In this work, the results obtained about the influence of each one of the components present in this type of detector in standard mammography beams is presented. The code MCNP5 was used. The results allowed the adaptation of the detector to the desired conditions.Artigo IPEN-doc 22873 Comparação entre duas câmaras de ionização do tipo lápis com comprimento de volume sensível de 30 cm2016 - CASTRO, MAYSA C. de; XAVIER, MARCOS; SILVA, NATALIA F.; CALDAS, LINDA V.E.A tomografia computadorizada (CT) vem crescendo devido aos avanços da tecnologia dos equipamentos, proporcionando uma dose maior no paciente, em relação aos demais exames de radiodiagnóstico, levando a uma preocupação com os pacientes. A dosimetria em CT é realizada com uma câmara de ionização do tipo lápis com comprimento de volume sensível de 10 cm. Os estudos têm mostrado a subestimação dos valores de dose. Foram desenvolvidas neste trabalho duas câmaras de ionização com comprimentos de volume sensível de 30 cm, que foram submetidas aos testes principais de caracterização, obtendo-se resultados dentro dos limites recomendáveis internacionalmente.Artigo IPEN-doc 20431 Avaliação de uma nova câmara de ionização tipo lápis para dosimetria em feixes de tomografia computadorizada2014 - CASTRO, MAYSA C. de; NEVES, LUCIO P.; SILVA, NATALIA F. da; SANTOS, WILLIAN de S.; CALDAS, LINDA V.E.