Heidelberg 2015 – scientific programme
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MS: Fachverband Massenspektrometrie
MS 14: Accelerator Mass Spectrometry and Applications 4
MS 14.1: Invited Talk
Friday, March 27, 2015, 11:00–11:30, PH/HS2
AMS detection of actinides at high mass separation — •Peter Steier1, Rosmarie Eigl2, Johannes Lachner1, Alfred Priller1, Francesca Quinto3, Aya Sakaguchi4, Stephan Winkler1, and Robin Golser1 — 1University of Vienna, Faculty of Physics, Vienna, Austria — 2Hiroshima University, Earth and Planetary Systems Science, Hiroshima, Japan — 3Institut für Nukleare Entsorgung, KIT, Eggenstein-Leopoldshafen, Germany — 4University of Tsukuba, Center for Research in Isotopes and Environmental Dynamics, Tsukuba, Japan
AMS is the mass spectrometric method with the highest abundance sensitivity, which is a prerequisite for measurement of the long-lived radioisotope 236U (t1/2=23.4 million years). The most successful application so far is oceanography, since anthropogenic 236U is present in the world oceans at 236U:238U from 10−11 to 10−8. We have explored methods to increase the sensitivity and thus to reduce the water volume required to 1 L or less, which significantly reduces the sampling effort. High sensitivity is also necessary to address the expected typical natural isotopic ratios on the order 236U:238U = 10−13, with potential applications in geology.
With a second 90∘ analyzer magnet and a new Time-of-Flight beam line, VERA is robust against chemical impurities in the background, which e.g. allows measuring Pu isotopes directly in a uranium matrix. This simplifies chemical sample preparation for actinide detection, and may illustrate why AMS reaches lower detection limits than other mass spectrometric methods with nominally higher detection efficiency.