Berlin 2005 – wissenschaftliches Programm
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A: Atomphysik
A 13: Poster HU 2
A 13.47: Poster
Dienstag, 8. März 2005, 08:30–18:30, Poster HU
Quantitative investigation of the enhancement of x-ray fluorescence by photoelectron secondary excitation — •B. Beckhoff1, M. Kolbe1, M. Müller1, G. Ulm1, A.G. Karydas2, Ch. Zarkadas2, T. Geralis 2, K. Kousouris 2, N. Kawahara3, T. Yamada3, and M. Mantler4 — 1Physikalisch-Technische Bundesanstalt, Abbestraße 2-12, 10587 Berlin, Germany — 2Institute of Nuclear Physics, N.C.S.R "Demokritos", Aghia Paraskevi 15310, Athens, Greece — 3R&D Lab., Rigaku Industrial Corp., Akaoji 14-8, Takatsuki, Osaka 569-1146, Japan — 4Institut für Festköperphysik, Technische Universität Wien, Wiedner Hauptstraße 8-10, A-1040 Wien, Austria
State-of-the-art quantitation in x-ray fluorescence analysis is mostly based on theoretical calculations accounting only for photon-in photon-out processes. However, as modern applications of x-ray spectroscopy often require drastically improved uncertainties, secondary processes (such as the excitation by photoelectrons created as a consequence of primary ionizations) have to be included. A straightforward approach for determining the impact of a secondary process on the fluorescence intensity requires sufficiently accurate knowledge of the flux of the incident monochromatic radiation, the solid angle of detection and the fluorescence count rate accessible through absolutely calibrated x-ray detectors. The energy dependence of the enhancement of K-shell fluorescence intensities by photoelectrons was investigated for several low Z elements ranging from carbon to silicon employing thin specimens. The experimental results and corresponding theoretical calculations are compared for selected cases.