Desenvolvimento de um sistema portátil de fluorescência de raios X por reflexão total usando uma geometria de detecção de saída rasante

• Ano de defesa: 2018
• Autor(a) principal: Santos, Ramon Silva dos
• Orientador(a): Anjos, Marcelino José dos
• Banca de defesa: Assis, Joaquim Teixeira de , Leitão, Catarine Canellas Gondim , Lopes, Ricardo Tadeu , Jesus, Edgar Francisco Oliveira de , Gonçalves, Elicardo Alves de Souza
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade do Estado do Rio de Janeiro
• Programa de Pós-Graduação: Programa de Pós-Graduação em Física
• Departamento: Centro de Tecnologia e Ciências::Instituto de Física Armando Dias Tavares
• País: BR
• Palavras-chave em Português: Fluorescência de raios X de saída rasante; GE-XRF; TXRF; Sistema portátil
• Palavras-chave em Inglês: Grazing exit X-ray fluorescence; GE-XRF; TXRF; Portable system
• Área do conhecimento CNPq: CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA::FISICA ATOMICA E MOLECULAR
• Link de acesso: http://www.bdtd.uerj.br/handle/1/12878

This work presents the development and characterization of a portable system of grazing exit X-ray fluorescence (GE-XRF) composed of a low power X-ray tube (gold anode), a semiconductor detector and quartz reflector. The GE-XRF system was evaluated and characterized through of the positioning tests in grazing exit angle, repeatability and reproducibility tests, sensitivity curve, detection limit, precision and accuracy. In addition, the results of a multielement sample was compared with the results of a system of grazing incidence X-ray fluorescence (GI-XRF). The repeatability and reproducibility tests of the GE-XRF system showed a coefficient of variation equal to 2.0 % and 4.0 %, respectively. Detection limits were in the range from 126 ng.g-1 to 15,9 μg.g-1 (15 ≤ Z ≤ 31). These values were compatible with results found in the literature for a portable GE-XRF system. The accuracy of the system was checked using a certified sample of bovine liver. The relative errors between measured and certified values were in the range of 2 to 22%, except of the elements S and P (26 and 40%, respectively). The quantitative results of a multielement sample were compared with the results of a GI-XRF system and both techniques presented good accuracy at the reference values, except for Ca. GE-XRF portable system developed in this work proved to be efficient, showing that it is possible to produce a grazing exit X-ray fluorescence system using a low power X-ray tube, a compact semiconductor detector and quartz reflector.