Contact
Prof. Dr. Anton Wallner
Head Accelerator Mass Spectrometry and Isotope Research
Head
anton.wallner
hzdr.de
Phone: +49 351 260 3274
Accelerator Mass Spectrometry and Isotope Research (FWIR)
In autumn 2011 the Ion Beam Center of HZDR has expanded its measurement capability by another highly-sensitive analytical method, accelerator mass spectrometry (AMS), which is used for the determination of long-lived radionuclides.
In contrast to ordinary decay counting, the "impatient" scientists do not wait for the disintegration of a radioactive nucleus. In fact, they determine the not-yet-decayed radionuclides by mass spectrometry, which is much more efficient.
There is a main advantage of using a high-energy accelerator for mass spectrometry: The background and interfering signals, resulting from molecular ions and ions with similar masses e.g. isobars, are nearly completely eliminated. Thus, AMS generally provides much lower detection limits in comparison to conventional mass spectrometry. Our AMS system offers excellent measurement capabilities also for external users.
In contrary to common low-energy AMS facilities in Germany and Europe, which have mainly specialized in radiocarbon analyses (14C), the HZDR-AMS was the first modern-type facility in the EU that runs at a terminal voltage of 6 MV. Maximum stability is guaranteed by producing the high-voltage of the accelerator by a high-frequency cascade generator.
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The benefits from using AMS for radiation protection, nuclear safety, nuclear waste, radioecology, phytology, nutrition, toxicology, and pharmacology research are obvious and manifold: Smaller sample sizes, easier and faster sample preparation, higher sample throughput and the redundancy for radiochemistry laboratories will largely reduce costs. Lower detection limits widen applications to shorter and longer time-scales and to sample types that could never be investigated before. Especially in environmental and geosciences, the determination of long-lived cosmogenic radionuclides like 10Be, 26Al, and 36Cl became more and more important. Using these nuclides dating of suddenly occurring (pre-)historic mass movements, e.g. volcanic eruptions, rock avalanches, tsunamis, meteor impacts, earth quakes and glacier movements, is possible. Additionally, glacier movements and data from ice cores give hints for the reconstruction of historic climate changes and providing information for the validation of climate model predicting future changes. Field work advices with respect to a sampling strategy for geomorphological applications can be downloaded here: Please contact us for new projects before sampling. |
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At the moment, we are able to determine at DREAMS the long-lived cosmogenic radionuclides listed in the table. AMS-measurements of other radionuclides, e.g. 44Ti, and stable nuclides (by so-called Super-SIMS) are under development. We are capable of measuring isotopic ratios (radioactive/stable) as low as 10-16. |
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Contact
Prof. Dr. Anton Wallner
Head Accelerator Mass Spectrometry and Isotope Research
Head
anton.wallnerhzdr.de
Phone: +49 351 260 3274
