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MS 12.3: Vortrag
Donnerstag, 12. März 2020, 14:30–14:45, f128
Towards the redetermination of the halflife of 32Si - Equilibrium charge distributions of 28Si in Ar — •Matthias Schlomberg, Christof Vockenhuber, and Hans-Arno Synal — Laboratory of Ion Beam Physics, ETH Zurich
The long-lived radionuclide 32Si is a cosmogenic nuclide 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 four decades. The SINCHRON collaboration with partners from PSI, CHUV, PTB and ETH aims at a comprehensive redetermination of the half-life of 32Si. Laboratory of Ion Beam Physics at ETH Zurich will perform the AMS measurements for the determination of the number of 32Si atoms in the samples used for the activity measurement. In addition to the challenge of the separation of 32Si from the isobar 32S, the absolute measurement is challenging, because no 32Si standards are available.
Therefore, the equilibrium charge state distribution of 28Si in Ar was measured in the energy range of 1-40 MeV using the external stripper at the TANDEM AMS facility. This information is necessary to find the optimal terminal voltage and for correction of mass fractionation in the stripping process.
In the first part of the presentation, the SINCHRON project will be introduced and motivated. Subsequently, our setup to measure the equilibrium charge distribution will be shown and the obtained data will be presented and discussed.