A Differential Flourescence Monitor for Elements of AdjacentAtomic Number but Grossly Different Concentrations

提出了一种能量色散X射线荧光分析技术，可以准确地测量样品中元素的小浓度(1%)，该样品的组成(90%)主要是原子序数(Z)相似但更大的元素。这种测量现在被来自主要元素的压倒性荧光信号所排除。这项拟议的技术将使用初级光子源、次级荧光器、一个或多个滤光片以及观测光谱的差示分析。该技术的主要特点是(1)通过适当地将入射能量移至主(K)X射线的激发以下来减少来自干扰元素的荧光，以及(2)通过使用差分方案引入次要效应。作为该技术的初步演示，我们将尝试说明在含铁98%(Z=26)的碳钢中检测1%水平的锰(Z=25)是可能的。将对该技术进行实验验证。

A technique is proposed whereby energy-dispersive X-ray fluorescence analysis can be made to accurately measure small concentrations ( 1%) of an element in a sample whose composition is dominated (90%) by an element of similar but larger atomic number (Z). Such measurement is now precluded by the overwhelming fluorescence signal from the dominant element. The proposed technique would employ a primary photon source, a secondary fluorescer, one or more filters, and differential analysis of the observed spectra. The key features of the technique are (1) reduction of the fluorescence from the interfering element by appropriately shifting the incident energy below the excitation of the dominant (K ) X rays and (2) incorporation of secondary effects by use of a differencing scheme. As an initial demonstration of the technique, we will attempt to show that it is possible to detect manganese (Z=25) at the 1% level in carbon steel having 98% iron (Z=26). Experimental verification of the technique will be undertaken.