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Geometric Considerations in EDXRF to Increase Fluorescence Intensities and Reduce Background

Published online by Cambridge University Press:  06 March 2019

Igor Tolokonnikoff
Igor Tolokonnikoff*
Affiliation:
Nuclear Radiometric Methods Moscow Geologic Prospecting Institute 23 MiKlukho-Maclay Str., GSP-7 117373 Moscow, U.S.S.R.
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Abstract

Two methods for improving the sensitivity of EDXRF will be presented. One method is to use a spherical geometry for the measurements. The analyzed specimen is made as a spherical layer (i.e., “orange rind”), with the exciting x-ray source and the detector being located in the inner surface of the specimen at opposite points on the diameter. The source radiation scattered into the detector is minimized by the 90° scattering angle at all points on the specimen. It has been shown that the sensitivity is improved by several times while earring out EDXRF measurements under conditions of spherical geometry as compared to the conventional flat arrangement.

The other method we have investigated makes use of polarized radiation. The source radiation is polarized by scattering from a thin, low atomic number material. Higher energy radiation from the x-ray tube passes through the polarizer, where it impinges on a secondary fluorescer. This secondary radiation is then polarized by the same scatterer as the primary radiation. A quasi-monoenergetic polarized source is produced with maximized intensity by these means. It has been shown experimentally that the use of this polarized source for excitation leads to detection limits which are several times lower in the whole range of moderate energy. It has further been shown that the use of the easily added secondary target to the standard orthogonal polarization geometry increases the polarized beam intensity by 10-15%.

Type
XIII. XRS Techniques and Instrumentation
Information
Advances in X-Ray Analysis , Volume 35 , Issue B: First Pacific-International Congress on X-ray Analytical Methods (PICXAM). Fortieth Annual Conference on Applications of X-ray Analysis, August 7-16, 1991 , 1991 , pp. 1009 - 1017
Copyright
Copyright © International Centre for Diffraction Data 1991

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References

1. Yu.N., Burmistenko and Tolokonnikoff, I. A., The use of spherical geometry of measurements in x-ray analysis, Izv. VTJZov Geologiya i razvedka Dep. N°2847-84 (in Russian).Google Scholar
2. Yu.N., Burmistenko, Tolokonnikoff, I. A. and ChernobrivetS, O. N., On possibility of improving the metrological characteristics of the x-ray analysis with the use of spherical geometry of measurements, Atomnaya enercriya 60(3):218 (1986) (in Russian).Google Scholar
3. Dzubey, T. G., Jarrett, B. V. and Jaklevic, J. M., Background reduction in x-ray fluorescence spectra using polarization, Nuclear Instruments and Methods 115: 297 (1974).10.1016/0029-554X(74)90459-5Google Scholar
4. Wobrauschek, P. and Aiginger, H., X-ray fluorescence analysis using intensive linear polarized monochromatic x-ray after Bragg reflection, X-Ray spectrometry 9(2):57 (1980).10.1002/xrs.1300090206Google Scholar
5. Ryqn, R. W., Sahrt, J. D., Wobrauschek, P., e.a., The use of polarized x-ray for improved detection limits in energy dispersive x-ray spectrometry. Advances in X-Rav Analysis 25: 63 (1982).Google Scholar
6. Yu.N., Burmistenko and Tookonnikoff, I. A., The apparatus for x-ray analysis of the content of substance, Inventor's Certificate USSR N-1224689 B.I. N-14 (1986).Google Scholar
7. Tolokonnikoff, I. A.. and Yu.N., Burmistenko, The apparatus for x-ray analysis of substance, Inventor's Certificate USSR N-1300353 B.I. N-12 (1987).Google Scholar
8. Tolokonnikoff, I. A., On the possibility of obtaining quasimonoenergetic polarized x-ray radiation in the moderate energy range, Atomnaya enerqiya 61(3):224 (1986) (in Russian).Google Scholar
9. Tolokonnikoff, I. A., To the problem on effectiveness of using the polarized secondary target radiation in energy-dispersive x-ray analysis, Izv. VUZov Geoloqiya i razvedka 3: 123 (1990) (in Russian).Google Scholar
10. Tolokonnikoff, I. A., Gorbatyuk, O. V. and Schekin, K. I., The use of exciting quasi-monoenergetic polarized radiation in energy-dispersivee X-ray analysis, Atomnaya. enerqiya. 69(2):115 (1990) (in Russian).Google Scholar