August 30, 2021 to September 3, 2021
University of Innsbruck
Europe/Zurich timezone

【337】Increasing the ionization yield for the detection of 236U and 233U by AMS

Sep 1, 2021, 6:30 PM
15m
Room B

Room B

Talk Nuclear, Particle- and Astrophysics (FAKT - TASK) Nuclear, Particle- & Astrophysics

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.

Primary 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)

Presentation materials