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MS: Fachverband Massenspektrometrie

MS 10: Posters III

MS 10.4: Poster

Donnerstag, 3. März 2016, 16:30–19:00, Empore Lichthof

AMS measurements of ¹⁰Be, ²⁶Al and ⁴¹Ca at DREAMS — •Andreas Scharf¹, Shavkat Akhmadaliev¹, Maurice Arnold², Pascal Bohleber³, Ingo Leya⁴, Silke Merchel¹, Georg Rugel¹, Thomas Smith⁴, René Ziegenrücker¹, and Lars Zipf³ — ¹HZDR, Dresden, Germany — ²CEREGE, Aix-en-Provence, France — ³Universität Heidelberg, Germany — ⁴University of Bern, Switzerland

DREAMS, the DREsden AMS-facility, is performing routine accelerator mass spectrometry for the isotopes ¹⁰Be, ²⁶Al, ³⁶Cl, ⁴¹Ca and ¹²⁹I. Sample ratios of ¹⁰Be/⁹Be as low as 8 x 10⁻¹⁵ (background-corrected) have been measured and an exposure age of about 330 years of a boulder of 3000 t in Nepal could be determined [1]. We could demonstrate that a by-product of ice core drilling, so-called drilling chips, are also suitable for ¹⁰Be analysis of ice cores, instead of using valuable ice core samples. A set of several in-house ²⁶Al and ⁴¹Ca standards has been made traceable to primary standards by cross-calibration [2]. Numerous ²⁶Al and ⁴¹Ca concentrations of meteorites could be determined, but for marine sediments there is still a need for a low-level (10⁻¹³) ²⁶Al standard. ICP-MS measurements have shown that the steel pins used to fix the CaF₂ sample material in the cathodes have high K-concentrations of (44.6 ± 2.2) µg/g. By replacing the steel pins with copper pins the ⁴¹K background during ⁴¹Ca measurements could be lowered by a factor of three.

Ref.: [1] W. Schwanghart et al., Science (2015), DOI:10.1126/ science.aac9865. [2] G. Rugel et al., Nucl. Instr. Meth.B (2015), in review.