X-Ray Fluorescence Analysis for Sodium, Fluorine, Oxygen, Nitrogen, Carbon, and Boron^*

Abstract Optimized vacuum spectrographic measurement of low-energy fluorescence has been found to yield counting rates and peak-to-background ratios which are enough to permit the extension of fluorescence analysis for elementary chemistry into the light-element range—sodium through boron. This is accomplished with an efficient, demountable ultrasoft X-ray source, with close coupling among source, crystal, and detector, with KAP and multilayered stearate analyzers, and with, optimized flow-propordonal counting. Specific methods for achieving peak-to-background ratios on practical samples containing these light elements are presented. The extension of these methods of light-element analysis with the use of curved long-spaced crystals for X-Ray macroprobe and electron microprobe measurements is discussed. The design and construction of multilayered soap film “crystals” for long-wavelength X-ray analysis is described.