Standarless Calibration for Micro-XRF with Capillary Optics

C..A. SOSA; H. J. SÁNCHEZ; R.D. PÉREZ

Carlos Paz

Conferencia; SARX 2014; 2014

The XRF emission from a bulk sample has not a linear dependence with elemental concentrations because of the so called matrix effects. The most versatile approach to correct matrix effects consists of the application of the Fundamental Parameter method (FP) which requires few calibration standards for the quantification of a wide range of matrices. For FP, the physical processes in the sample leading to the XRF emission are described by a set of analytical equations. It requires a database of fundamental parameters and the spectral distribution of the excitation radiation as well. For the Microanalysis by XRF (micro-XRF), the high intensity and anisotropy of the photon flux at the output of the focalization lens difficult a direct determination of the emergent spectrum. Different techniques have been used in the past to estimate the excitation spectrum using indirect measurements, such as attenuation of the primary intensity [1], x-ray scattering [2] and induced xray fluorescence in targets [3]. The first two methods are based on approximated theoretical models which produces limitations in accuracy