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Automated Determination of Optimum Excitation Conditions for Single and Multielement Analysis with Energy Dispersive X-Ray Fluorescence Spectrometry

Published online by Cambridge University Press:  06 March 2019

Wolfhard Wegscheider ,
Bruce B. Jablonski  and
Donald E. Leyden
Wolfhard Wegscheider
Affiliation:
Department of Chemistry, University of Denver Denver, Colorado 80208
Bruce B. Jablonski
Affiliation:
Department of Chemistry, University of Denver Denver, Colorado 80208
Donald E. Leyden
Affiliation:
Department of Chemistry, University of Denver Denver, Colorado 80208
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Abstract

The determination of optimal excitation conditions for energy dispersive x-ray fluorescence is particularly critical for multielement analysis covering a wide range (viz. 10 or 20 keV) of the spectrum. Functions that quantitatively describe the spectral quality are used as objective functions in pattern search algorithms. It is shown that the filters can be arranged in a definite order, at least with respect to the energy of the K-absorption edge of the tube and can therefore be employed as a dimension in the optimization process. Of the algorithms that were compared, the Nelder-Mead and Routh-Swartz-Denton versions of the sequential simplex search gave the best results if the excitation voltage and the current could be controlled in small increments. If the optimization includes dimensions with a few discrete stages (e.g. filters) the fixed size simplex proved to be of greatest value. The functions can be weighted to reflect special interest in one or more elements. Conditions for increasing the counting time and terminating the search are discussed.

Type
Research Article
Information
Advances in X-Ray Analysis , Volume 22: Twenty-Seventh Annual Conference on Applications of X-ray Analysis, August 1-4, 1978 , 1978 , pp. 433 - 451
Copyright
Copyright © International Centre for Diffraction Data 1978

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