Mainz 2017 – wissenschaftliches Programm
MS 9.9: Vortrag
Donnerstag, 9. März 2017, 16:30–16:45, RW 2
Tackling challenges in AMS sample preparation — •Silke Merchel1, Loic Le Bras1, Sabrina Gurlit1, Georg Rugel1, Andreas Scharf1, Thomas Opel2, and Sebastian Wetterich2 — 1HZDR, Dresden, Germany — 2AWI, Potsdam, Germany
Since 2009 the DREAMS (DREsden Accelerator Mass Spectrometry) facility offers users to do their own sample preparation for AMS targets. A large number of samples from interdisciplinary research topics such as astronomy, climate, cosmochemistry and geology could be transformed into BeO, Al2O3, AgCl and CaF2 showing reasonable to excellent performance Rugel et al., this DPG.. However, besides our constant approach to become a little better every day, sometimes very new challenges can arise due to the low availability of the sample material, low radionuclide concentration or a possible contamination of the sample with disturbing elements and nuclides. Two examples:
Ice samples are always in our focus. As we were facing problems with 10Be contamination in "dirty" ground ice, we measured 36Cl and natCl by isotope dilution in permafrost ice wedge samples as heavy as 1.6 kg. The chemical yield of AgCl was only 20-35% (and is a function of total natCl), which might be improved by preconcentration steps.
For the determination of in-situ or atmospheric 26Al in marine and terrestrial sediments e.g. Gärtner et al., this DPG., we had sometimes unaccountable low chemical yields, which seems to be partially due to redissolving aluminium hydroxide in the last washings.
Thanks to A. Gärtner, P. Ludwig, D. Rodrigues and several students for providing/processing samples.