Erlangen 2018 – wissenschaftliches Programm
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MS: Fachverband Massenspektrometrie
MS 8: Accelerator Mass Spectrometry 3
MS 8.2: Vortrag
Donnerstag, 8. März 2018, 14:45–15:00, R 1.020
Developments towards AMS of 182Hf with ILIAMS — •Martin Martschini1, Xiaohe Zhang1, Dag Hanstorp2, Johannes Lachner1, Alfred Priller1, Peter Steier1, Paul Wasserburger1, and Robin Golser1 — 1VERA Laboratory, University of Vienna - Faculty of Physics, Austria — 2Department of Physics, University of Gothenburg, Sweden
The Ion Laser InterAction Mass Spectrometry (ILIAMS) technique is currently developed at the Vienna Environmental Research Accelerator (VERA). It provides suppression of isobar contaminants in negative ion beams for AMS via selective laser photodetachment in a gas-filled radio frequency quadrupole (RFQ). Measurement of the longlived trace isotope 182Hf (T1/2 = 8.9 Ma) is one of the main objectives of this project. 182Hf is of high astrophysical interest, however, despite substantial efforts, could not be measured at its natural abundance level with conventional AMS so far due to strong isobaric interference from stable 182W.
With He-O mixtures as buffer gas in the RFQ, suppression of 182WF5− vs 180HfF5− by up to 106 has recently been achieved with W-spiked targets. Mass analysis of the ejected anion beam identified the formation of oxyfluorides as an important reaction channel. Furthermore, first tests with 182Hf reference materials have been conducted. In this contribution, we will give details on these measurements including the overall detection efficiency and the present sensitivity limit. In addition, we will report on a survey of several sputter materials for highest negative ion yields of HfF5−.