Erlangen 2018 – wissenschaftliches Programm
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MS: Fachverband Massenspektrometrie
MS 8: Accelerator Mass Spectrometry 3
MS 8.3: Vortrag
Donnerstag, 8. März 2018, 15:00–15:15, R 1.020
Progress in detection of Cs isotopes with ILIAMS at VERA — •Johannes Lachner, Martin Martschini, Alfred Priller, Peter Steier, Xiaohe Zhang, and Robin Golser — VERA Laboratory, University of Vienna, Faculty of Physics, Austria
The development of Ion Laser InterAction Mass Spectrometry (ILIAMS) establishes new prospects for sensitive Accelerator Mass Spectrometry analyses of isotopic systems. The reliability of the new method was proven with measurements of 36Cl and 26Al. Inside a radiofrequency quadrupole filled with ≈0.2 mbar He buffer gas the isobars 36S and 26Mg could be suppressed by up to 10 orders of magnitude via laser photodetachment using 532 nm photons from a 18 W cw laser.
Further application of the technique is expected by studying isotopic systems that are new to AMS: Here, one focus is on the detection of the trace isotopes 135,137Cs as the measurement of these two Cs isotopes has widespread applications in the environmental sciences for dating or source apportionment. In this case a suppression of the isobars 135Ba and 137Ba is required.
I will present the benefits of the use of either Cs− or CsF2− as primary extracted negative ion and their performance in the ion source and transmission through the ion cooler. By generating the di-fluoride anions CsF2− and BaF2− a suppression of the 135,137Ba isobars can be accomplished using 532 nm photons in the photodetachment process. The suppression furthermore profits from an additional chemical effect inside the ion cooler, which is enhanced by an admixture of O2 to the He buffer gas.