Speaker
Michael Kern
(University of Vienna, Faculty of Physics - Isotope Physics)
Description
The detection efficiency of Accelerator Mass Spectrometry for long lived uranium isotopes ($^{236}$U or $^{233}$U) is mainly limited by the rather low yield of the corresponding negative ions extracted from a caesium sputter ion source (≈ 10$^{–4}$). With our new sample preparation method environmental U is embedded in only 200 µg Fe$_2$O$_3$ matrix which is then mixed with PbF$_2$. Extracting U as UF$_5^–$ instead of UO$^-$ yields an improvement in detection efficiency by more than a factor 10. UF$_5^–$ extraction seems advantageous for the suppression of molecular isobaric background ($^{232}$ThH$^{3+}$, $^{235}$UH$^{3+}$) and allows operation at lower He stripper gas pressure.
Author
Michael Kern
(University of Vienna, Faculty of Physics - Isotope Physics)
Co-authors
Robin Golser
(University of Vienna, Faculty of Physics - Isotope Physics)
Karin Hain
(University of Vienna, Faculty of Physics - Isotope Physics)
Clemens Schmid
(University of Vienna, Faculty of Physics - Isotope Physics)
Peter Steier
(University of Vienna, Faculty of Physics - Isotope Physics)
Andreas Wiederin
(Universität Wien, Faculty of Physics - Isotope Physics)
