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MS: Fachverband Massenspektrometrie
MS 10: Accelerator Mass Spectrometry II
MS 10.5: Vortrag
Freitag, 14. März 2025, 12:15–12:30, HS 2 Chemie
Developments towards detection of 26Al at ALIS — •Ferhat Altun, Markus Schiffer, Stefan Heinze, Timm-Florian Pabst, Gereon Weingarten, and Dennis Muecher — Institute for Nuclear Physics, University of Cologne, Germany
To expand the list of measurable isotopes for AMS, the Anion Laser Isobar Separator (ALIS) was installed at CologneAMS. The system uses element-selective photo-detachment for the suppression of the high abundant isobars. The process of laser isobar interaction requires the superposition of a high intense laser with the anion beam. For the decoupling of the laser and the anion beam, an electrostatic deflector with a hole in the outer electrode is used. Holes in electrodes of electrostatic devices lead to unwanted field inhomogeneities. Therefore, we developed an additional correction electrode for electrostatic deflectors, that is able to correct the inhomogeneity and hence ensures a precise energy filtering. In this talk, the electric field measurements of the electrostatic deflector will be presented including our newly developed measurement technique. The main focus of the ALIS setup is the measurement of environmental (90Sr, 135Cs), and cosmogenic isotopes (26Al, 41Ca). For the benchmark test of the new setup, we measured the efficiency and level of detection of an isotope that is routinely measured at CologneAMS, which can be improved for the users of the facility. Therefore, we aim to measure 26Al with ALIS by use of the prolific molecular injection (AlO−) where the suppression of 26MgO is required. The measured ionization efficiencies of the ion beams will be discussed during the talk.
Keywords: Aluminium(-oxide) ionization efficiency; Isobar suppression; Electrostatic deflector; Electric field inhomogeneity; Field correcting electrode