Synchrotron radiation micro-X-ray fluorescence analysis: A tool to increase accuracy in microscopic analysis

摘要

Microscopic X-ray fluorescence (XRF) analysis has potential for development as a certification method and as a calibration tool for other microanalytical techniques. The interaction of X-rays with matter is well understood and modelling studies show excellent agreement between experimental data and calculations using Monte Carlo simulation. The method can be used for a direct iterative calculation of concentrations using available high accuracy physical constants. Average accuracy is in the range of 3-5% for micron sized objects at concentration levels of less than 1 ppm with focused radiation from SR sources. The end-station ID18F of the ESRF is dedicated to accurate quantitative micro-XRF analysis including fast 2D scanning with collection of full X-ray spectra. Important aspects of the beamline are the precise monitoring of the intensity of the polarized, variable energy beam and the high reproducibility of the setup measurement geometry, instrumental parameters and long-term stability.