Crystallographic Aspects of Extra Reflections in X-Ray Spectrochemical Analysis

Abstract

In x‐ray spectrochemical analysis, a given crystal monochromator can give rise to higher‐order reflections of the incident wavelength, which may be ascribed to the planes (nh nk nl), which are parallel to the principal planes (hkl). In addition to these, however, there may occur reflections due to other sets of planes which are slightly tilted with respect to (hkl). These reflections may lead to undesirable spectral interferences. The identification of these undesirable reflections and their dependence upon choice of various angular divergence parameters, on wavelength, and on the selection and orientation of the monochromators are discussed in terms of an instrumental figure of reflection and a detecting volume in reciprocal space. Topaz and quartz are used as specific examples of the problem.