Self‐absorption of As, Se and Br for their Kβ2 and Kβ1,3 radiations and its effect on intensity ratio measurements (chemical state analyses of As, Se and Br by X‐Ray Method. 3)

Abstract

AbstractA dependence of the observed Kβ2/Kβ1,3 intensity ratios of As, Se and Br on their concentrations in measured samples was found in a study of the use of these ratios in chemical state analysis. This paper includes the experiments and discussion on this concentration effect, which is caused by the large difference between the self‐absorption coefficients of each element for its Kβ2 and Kβ1,3 radiations. An x‐ray spectrometer was used for the measurements of the intensity ratios and absorption coefficients. Since the Kβ2 radiation of each element has a wavelength shorter than the Kβ1,3 radiation and longer than the K absorption edge, the self‐adsorption coefficient of the Kβ2 radiation was presupposed to be smaller than that of the Kβ1,3 radiation. The results of experiments, however, were contrary to the supposition. The observed self‐absorption coefficients of these elements for their Kβ2 radiations were 1.4–2.2 times those of their Kβ1,3 radiations, depending on the chemical states of the elements as absorbers or x‐ray emitters. These values gave a solution to the concentration effect. The correction of the effect allows the inherent intensity ratios to be determined which may then be used for chemical state analysis.