15.3. Modelling XRF Data

X-ray fluorescence (XRF) is the emission of X-rays of well-defined energies that correspond to the known electronic enery levels of atoms. This phenomenon is closely associated to the quantum understanding of atom and the use of X-rays of certain characteristic energies to identify the presence of particular elements has been used very soon after the discovery of X-rays. While the basic XRF phenomenon and the use of X-ray emission to identify the presence of certain atomic species are well understood, the quantivative analysis of X-ray fluorescence spectra to accurately determine atomic concentrations is a bit complicated by several different factors. With these complicating factors accounted for, accurate elemental abundances can be extracted from XRF data. Here, we’ll cover some of the details of what makes XRF analysis somewhat challenging and discuss how to use Larch to analyze XRF data to extract quantitative values for concentrations.