The surface geometrical structure effect in in situ X-ray fluorescence analysis of rocks

The results of investigating the effect of surface geometrical structure in in situ X-ray fluorescence elemental analysis of rocks are presented. This effect can be estimated quantitatively by three parameters. the source–sample distance (H0), the surface peak–valley amplitude (ΔH) and the frequency number (n) of convex or concave surfaces within the effective detection area of the probe. Theoretical and experimental results show that three measures can be used to reduce the surface geometrical structure effect to a minimum in the X-ray fluorescence analysis of rock. (1) Taking the ratio of the intensities of characteristic-to-scattered radiation as a basic parameter and making the energies of characteristic and scattered radiations as similar as possible; (2) taking the average of the ratios of the intensities of characteristic-to-scattered radiation in the area of interest; (3) avoiding convex or concave morphology when measuring within the effective detection area of the probe.