A procedure using polychromatic excitation and scattered radiation for matrix correction in x-ray microfluorescence analysis

A fundamental-parameters method using x-ray tube excitation was developed for use in the x-ray micro-fluorescence analysis of flat, optically polished geological specimens. In this procedure, the coherent and incoherent tube target lines scattered from the sample are used to calculate the average atomic number and mass thickness of the sample. The polychromatic tube spectral distribution is calculated from a published algorithm. Since elements such as carbon, hydrogen and oxygen are unmeasurable, their contribution for the purposes of matrix correction can be represented by two hypothetical elements which span each side of the calculated average atomic number of the low-Z matrix. This procedure is applicable to infinitely thick samples and also those of intermediate thickness, and was tested on glasses of known composition.