Accuracy of the fundamental parameter method for x-ray fluorescence analysis of rocks

摘要

The accuracy of quantitative X-ray fluorescence (XRF) analysis of rocks by means of the fundamental parameter (FP) method is predetermined by the completeness of the characteristic X-radiation model, the degree of uncertainty in the FPs and the correctness of the calculation algorithms. This paper contains the results of a study of these factors for the XRF analysis of rocks that differ greatly in their elemental compositions. In order to improve the model of characteristic X-radiation, the significance of photoelectrons is thoroughly examined in this paper, and the effects of divergence of the primary radiation beam is assessed. The FP uncertainties are studied in this paper, and equations are derived to calculate the fluorescence yield, probabilities of serial line radiation and absorption jumps. Equations are proposed to calculate the mean electron energy and spectral intensity of X-ray tube radiation. A numerical integration algorithm is optimized by wavelengths, with allowance for the X-ray tube bremsstrahlung radiation. A software program is developed to calculate the characteristic radiation intensity and element compositions. Metrologic characteristics of the FP method based XRF analysis allow for its use in rock studies. Copyright (C) 2002 John Wiley Sons, Ltd. [References: 32]