Hannover 2010 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MS: Fachverband Massenspektrometrie
MS 6: Beschleunigermassenspektrometrie und Anwendungen II
MS 6.6: Vortrag
Mittwoch, 10. März 2010, 17:45–18:00, F 428
Recent advances in AMS of 36Cl with a 3-MV-tandem — •Martin Martschini, Oliver Forstner, Robin Golser, Walter Kutschera, Tobias Orlowski, Stefan Pavetich, Alfred Priller, Peter Steier, and Anton Wallner — VERA Laboratory, Universität Wien - Fakultät für Physik - Isotopenforschung, Austria
Accelerator mass spectrometry (AMS) of 36Cl (t1/2 = 0.30 Ma) at natural isotopic concentrations requires high particle energies for the separation from the stable isobar 36S and so far was exclusively the domain of machines with at least 5 MV terminal voltage.
At VERA (Vienna Environmental Research Accelerator) we had performed the first 36Cl exposure dating measurement with a 3-MV tandem accelerator, operating our machine up to 20% above the nominal value, using foil stripping and a split-anode ionization chamber. We evaluated the performance of various detector setups for 36Cl. With the ionization chamber and an additional energy signal from a silicon strip detector, we now achieved an equally good 36S-suppression at 3 MV terminal voltage compared to 3.5 MV in our previous measurements. In addition, we improved ion source conditions and target backing materials with respect to sulfur output and cross contamination. We believe that 36Cl measurements, which are competitive to larger tandems, are now possible.
Recently we started investigations on energy straggling in different counting gases. Comparison of first experimental data with simulations and published data yielded interesting insight into the physics underlying the detectors.