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Heterogeneity Effects in X-Ray Analysis*

Published online by Cambridge University Press:  06 March 2019

Fernand Claisse  and
Claude Samson
Fernand Claisse
Affiliation:
Department of Natural Resources of the Province of Quebec Quebec, Canada
Claude Samson
Affiliation:
Department of Natural Resources of the Province of Quebec Quebec, Canada
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Abstract

A fundamental quantitative treatment of the heterogeneity effects in X-ray fluorescence has been made. The theory predicts that the grain-size effect appears only in a limited region of grain sizes which depends on the wavelength of the primary radiation and the nature of the compounds in the mixture. With monochromatic radiation, the fluorescence intensity showed increase or decrease by a factor of a few units as grain size is decreased, A factor as large as 12, the theoretical value, has been observed in one particular experiment. Usually the grain-size effect can be eliminated by intensive grinding. For the light elements fine grinding is disastrous if long wavelengths are used. By an appropriate choice of the wavelength it is possible to eliminate the effect even without grinding. The mathematical treatment also predicts, but less rigorously, a grain-size effect in X-ray diffraction.

The effect on the fluorescence intensities by changes in the chemical composition of the grains that contain the fluorescent element is predicted by the theory.

These findings are discussed in relation to the analysis of elements when polychromatic beams are used.

Type
Research Article
Information
Advances in X-Ray Analysis , Volume 5: Tenth Annual Conference on Applications of X-ray Analysis, August 7-9, 1961 , 1961 , pp. 335 - 354
Copyright
Copyright © International Centre for Diffraction Data 1961

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Footnotes

*

Associate professor, Mining and Metallurgy Department, Université Laval, Quebec, and chief physicist, Department of Natural Resources of the Province of Quebec.

*

Published by permission of the Deputy Minister of Natural Resources.

References

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