Determination of x-ray excitation spectra in micro-XRF spectrometry with capillary optics

SOSA, C.; SÁNCHEZ H.J.; PÉREZ R.D.; LEANI J.; SBARATO, V.

SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2016 vol. 117 p. 23 - 28

0584-8547

The high intensity of the x-ray tube and the anisotropy of the photon flux complicate the direct determination of the emergent spectrum of the lens while performing microanalysis by x-ray fluorescence. An alternative is an indirect determination based on measurement of induced x-ray fluorescence in a set of targets. In this work the x-ray excitation spectrum is determined by an iterative deconvolution process of the fundamental parameter expression for the x-ray fluorescence intensities. The method has the advantage that it does not requires any assumption about the energy distribution of the x-ray source or the energy dependence of the lens transmission. Numerous XRF targets of pure elements with emission lines covering the full energy range of the x-ray source are employed. The only requirement on the targets is a high homogeneity in its composition. In fact, it does not impose any condition on the samples thickness. The accuracy observed in the validation process is similar to that reported with alternative approaches: 5% for main components, 10% for minor elements and 15% for trace elements.