Freiburg 2024 – wissenschaftliches Programm
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MS: Fachverband Massenspektrometrie
MS 9: Accelerator Mass Spectrometry IV
MS 9.4: Vortrag
Freitag, 15. März 2024, 12:00–12:15, HS 3042
Towards the Redetermination of the Half-life of 32Si - AMS Measurement — •Matthias Schlomberg, Christof Vockenhuber, and Hans-Arno Synal — Laboratory of Ion Beam Physics, ETH Zurich
32Si is a cosmogenic, long-lived radionuclide with potentially interesting applications for dating the recent past. However, its half-life of about 150 years is still not known with sufficient precision despite several independent measurements over the past four decades. The SINCHRON collaboration with partners from PSI, CHUV, PTB and ETH aims at a comprehensive redetermination of the half-life of 32Si.
The Laboratory of Ion Beam Physics (LIP) at ETH Zurich will perform the AMS measurements using the 6 MV-Tandem facility for the determination of the number of 32Si atoms in the samples used for the activity measurement. This task is especially challenging since an absolute measurement must be performed without having any standard material available.
Therefore, we developed a dedicated method using a passive gas absorber in front of a gas ionization detector for separation of 32Si from its isobar 32S at 30 MeV and 40 MeV which is compared to the standard method of using a gas-filled magnet. In this talk, the measurement setup and first results are presented and discussed. Furthermore, an outlook is given for a possible improvement and application to natural samples.
Keywords: AMS; Absolute Measurement; Silicon-32