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.
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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