| Инд. авторы: | Lavrent'ev Yu.G, Usova L.V. |
| Заглавие: | Theoretical absorption coefficients in the electron probe microanalysis |
| Библ. ссылка: | Lavrent'ev Yu.G, Usova L.V. Theoretical absorption coefficients in the electron probe microanalysis // Аналитика и контроль. - 2016. - Vol.20. - Iss. 1. - P.15-22. - ISSN 2073-1442. - EISSN 2073-1450. |
| Внешние системы: | DOI: 10.15826/analitika.2015.20.1.006; SCOPUS: 2-s2.0-85015241968; |
| Реферат: | eng: Two methods of determining X-ray attenuation coefficients μ are known: theoretical, which uses quantum mechanics calculations, and experimental. Experimentally obtained coefficients are widely used in electron probe microanalysis (EPMA), including the quantitative analysis of low atomic number elements (Be to F) in the ultra-long wavelength range. Nonetheless, the uncertainty of experimental coefficients is quite high. Even though theoretical attenuation coefficients were discovered later and are available only for X-ray energy more than 1 keV, they have already shown great promise. In the EPMA practice, theoretical attenuation coefficients may be used together with an approximation of the dependence of μ on X-ray photon energy, E. X-ray energy in EPMA has an upper limit of about 10 keV where only radiation absorption needs to be accounted for while the scattering can be neglected. Comparison of the existing methods of approximation of energy dependence on mass absorption coefficient t revealed that all of them are based on J. Scofield theoretical calculations and yield similar results. For the practical purposes, a method proposed by Ebel et al. seems to be most suitable. The use of the theoretical coefficients for rock-forming mineral analysis and for the M-edge absorption spectra (elements with atomic numbers 76 - 83 and rare earth elements) produced promising results. Applying theoretical coefficients together with calculating the absorption correction using phi-rho-z-modelling leads to the improved accuracy of quantitative analysis.
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| Ключевые слова: | X-ray absorption; Electron probe microanalysis; Approximation; |
| Издано: | 2016 |
| Физ. характеристика: | с.15-22 |