Erlangen 2018 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 51: Poster: Quantum Optics and Photonics IV
Q 51.29: Poster
Mittwoch, 7. März 2018, 16:15–18:15, Redoutensaal
Characterization of a source of slow metastable Kr atoms — •Ergin Simsek, Markus Kohler, Carsten Sieveke, Pablo Woelk, Christoph Becker, and Klaus Sengstock — Universität Hamburg, Deutschland
Kr85 is produced only anthropogenically by nuclear fission. Therefore its concentration in the atmosphere has increased since the beginning of the nuclear age. With its half life of 10.76 years, Kr85 can be used as a tracer for measuring the regeneration cycles of young ground waters.
For this application we are developing a measurement chain including sampling, sample preparation and an isotope-selective concentration measurement. For the determination of Kr85 content our setup is based on the Atom Trap Trace Analysis (ATTA) method which is sensitive to the parts-per-trillion level.
The measurement device uses a 2D-3D magneto-optical trap (MOT), capable of capturing and counting specific isotopes down to the single atom regime. As it is not possible to cool and trap Kr from the ground state, we first prepare the atoms to a metastable state.
To avoid cross contamination we implement an all-optical excitation scheme which includes an in-house developed VUV lamp emitting 123 nm and a 819 nm diode laser system. Because of the complex relationship between excitation and capturing dynamics within the 2D MOT we evaluate spatial distribution of the excitation by measuring the loading rate of the 3D MOT.