To apply the fundamental parameters method at the con focal setup the knowledge of the sensitivity of the spectrometer is required\nwhich depends on the characteristics of two X-ray lenses: one in the excitation channel and another in the detection channel.\nFor the particular case of poly chromatic excitation, the theory shows that the focalization properties of the excitation lens for all\nincident energies affect the X-ray fluorescence intensity. Therefore the traditional calibration method based on the measurement\nof standard samples becomes unstable since the number of required fitting parameters is too high. To reduce these parameters a\nprevious characterization of the excitation lens by a simulation program was employed giving rise to a simplified con focal setup\ncalibration.The developed calibration method was applied for a con focal spectrometer implemented in the Brazilian Synchrotron\nRadiation Source (LNLS) with white be am.The experimental parameters of the sensitivity were obtained from depth profile analysis\nof several pure thin films. The calibrated con focal setup was used to quantify reference standards in order to validate the calibration\nprocedure. Our results for elemental concentrations show relative errors less than 15% for the quantitative analysis of a light matrix\nreference standard.
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