Accurate Cross Sections for Microanalysis |
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Authors: | Peter Rez |
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Affiliation: | Department of Physics and Astronomy and Center for Solid State Science, Arizona State University, Tempe, AZ 85287 |
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Abstract: | To calculate the intensity of x-ray emission in electron beam microanalysis requires a knowledge of the energy distribution of the electrons in the solid, the energy variation of the ionization cross section of the relevant subshell, the fraction of ionizations events producing x rays of interest and the absorption coefficient of the x rays on the path to the detector. The theoretical predictions and experimental data available for ionization cross sections are limited mainly to K shells of a few elements. Results of systematic plane wave Born approximation calculations with exchange for K, L, and M shell ionization cross sections over the range of electron energies used in microanalysis are presented. Comparisons are made with experimental measurement for selected K shells and it is shown that the plane wave theory is not appropriate for overvoltages less than 2.5 V. |
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Keywords: | electron beam x-ray microanalysis electron ionization cross sections x-ray microanalysis microanalysis |
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