Calculation of the contributions of scattering effects to the X-ray fluorescent intensities for light matrix samples

The contributions of scattering effects to the X-ray fluorescent intensities were calculated by considering the intensity of scattered primary fluorescence radiation that is scattered into the direction of detector, the secondary enhancement by coherent scattering radiation and incoherent scattering radiation for light matrix samples on the basis of the theoretical calculations. Relative intensities for nine different characteristic X-ray lines for the synthesized fused disks were calculated and compared with the measured relative intensities. It was found from this study that the contributions of scattering effects to the fluorescent intensities of analytes in fused disk samples are sizeable. Moreover, the magnitude of contribution of scattering effects increases with the increase of atomic number of analyte or/and the decrease of the content of the fluorescent element in the fused disk samples, which is about several percents of that excited by primary radiation, or even more than 10% for PbLβ1. The average relative error of the calculated relative intensities compared with the measured values is 0.93% after scattering effects was considered, while the average relative error of the values calculated by NRLXRF for the same lines is 2.75%. The calculated relative intensities after considering the scattering effects are more agreeable to the measured values. Therefore, more accurate results for fundamental parameter method are expected with the consideration of scattering effects, especially for light matrix samples.