Erlangen 2018 – wissenschaftliches Programm
MS 5.2: Vortrag
Mittwoch, 7. März 2018, 14:30–14:45, R 1.020
Beryllium-7 at DREAMS — •Georg Rugel1, Silke Merchel1, Andreas Scharf1, Rebecca Querfeld2, Georg Steinhauser2, and Collin Tiessen1,3 — 1HZDR, Dresden, Germany — 2IRS Hannover, Germany — 3AEL AMS Laboratory, Canada
Half-lives of routine AMS nuclides range from thousands to millions of years. We measured short-lived 7Be (T1/2 = 53.2 d) at the DREsden AMS-facility (DREAMS)  as low as 90 mBq, which can be challenging for rapid γ-counting. Simultaneous determination of 7Be and 10Be (T1/2 = 1.387 Ma) via AMS is advantageous for improved understanding of production, transport, and deposition of atmospherically produced 7,9,10Be .
Data was normalized to a 7Be sample produced via 7Li(p,n)7Be, measured by γ-counting and chemically processed to BeO (7Be/9Be ≈ 10−12). The isobar 7Li is completely eliminated by chemistry and the degrader foil technique (7Be4+, 10.2 MeV). The blank ratio of 5× 10−16 7Be/9Be (0.8 mBq) and simple and fast chemistry allows for the measurement of rainwater samples, collected in Germany, as small as 10 ml corresponding to a few times 10−14 7Be/9Be [3,4].
Thanks to D. Bemmerer (HZDR) and G. György (ATOMKI, Hungary) for help with the 7Be normalization material.
Ref.:  G. Rugel et al., NIMB 370 (2016) 94.  A.M. Smith et al., NIMB 294 (2013) 59.  R. Querfeld et al., JRNC 314 (2017)521.  C. Tiessen et al. JRNC (submitted).