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A Combined Focusing X-Ray Diffractometer and Nondispersive X-Ray Spectrometer for Lunar and Planetary Analysis

Published online by Cambridge University Press:  06 March 2019

K. Das Gupta ,
Herbert W. Schnopper ,
Albert E. Metzger  and
Rex A. Shields
K. Das Gupta
Affiliation:
California Institute of Technology, Pasadena, California
Herbert W. Schnopper
Affiliation:
Cornell University, Ithaca, New York
Albert E. Metzger
Affiliation:
California Institute of Technology, Pasadena, California
Rex A. Shields
Affiliation:
California Institute of Technology, Pasadena, California
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Abstract

An instrument is described which is intended to perform a dual purpose (elemental-structural) analysis consistent with the environmental conditions implied by lunar or planetary operation. The dififractometer section is based on a modified Seeman-Bohlin focusing principle in which a sharp-line focus target, a powdered sample, and a movable detector slit all lie on the focusing circle. The convolution of the projections on the focal circle, of a narrow receiving slit on the detector, the line focus target, combined with a high dispersion produce higher resolution and intensity than is common with Bragg focusing diflfractorneters with simitar instrumental parameters. The range of d-spacings covered is from 1 to 7 Å (chromium target). The chemical analysis section of the instrument utilizes the fluorescent X-rays produced in the specimen by the primary beam. A proportional counter and pulse-height anaiyzer accomplish detection and energy discrimination. Resolution is low, but the analysis can distinguish between elements in the range of atomic numbers 11 to 29. Data from a breadboard model is presented. The entire unit, although primarily intended to meet the requirements of space, performs equally well as a routine laboratory analyzer. The horizontal, stationary nature of the specimen holder suggests several specific applications.

Type
Research Article
Information
Advances in X-Ray Analysis , Volume 9: Fourteenth Annual Conference on Applications of X-ray Analysis, August 25-27, 1965 , 1965 , pp. 221 - 241
Copyright
Copyright © International Centre for Diffraction Data 1965

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References

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