Caracterização de um sistema de fluorescência de raios X por dispersão em energia para análise quantitativa de ligas metálicas

• Autor(a) principal: Batista, Rafaela Tavares
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/12905
• topic: X-Ray Spectrometry; X-Ray Fluorescence; ARTAX 200; Espectrometria de raios X; Fluorescência de raios X; ARTAX 200; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA::FISICA NUCLEAR

This paper presents procedures for characterization of a commercial system for portable X-Ray Fluorescence energy dispersive, the ARTAX 200, along with its calibration process. The system consists of an X-ray tube with molybdenum anode and a Silicon Drift Detector XFlash cooled by Peltier effect. The procedure for the characterization of the system was conducted using a reference sample containing Iron Chromium. We also used the certified samples (National Bureau of Standards) D840, D845, D846, D847 and D849 to perform the calibration of the system. The calibration process was conducted by three different methods: Methodology 1, Methodology 2 and Methodology 3, to evaluate them which present better results. The characterization system ARTAX 200 was performed by running stability tests of the X-ray tube, repeatability, reproducibility, resolution in energy of the system, limit of detection and verification of the geometric center of the beam. The results of the stability tests showed an average coefficient of variation of less than 2% repeatability test showed average values lower than 0.5%. The reproducibility showed a coefficient of variation of less than 1.5% which. The verification of the geometric center is aligned with the center of the great beam in two of the three directions of the Cartesian plane. The energy resolution of the system presented to the energy of 5.9 keV a resolution of 150 eV. The detection limit values were less than 1% of the Cu Si. In evaluating methodology for calibrating the best result was obtained with the methodology 3. Comparing the results with other portable XRF systems shows that the ARTAX 200 presents superior efficiency with respect to the parameters analyzed.