Speaker
Description
At the boundary between atomic physics and nuclear physics one can find exotic decay modes such as the case of 205-Tl. Being a stable nuclear species on earth, 205-Tl starts to beta decay, when it is fully ionized. This so-termed bound-state beta decay plays an indirect, yet crucial role in dating our solar system via the nuclear chronometer 205Pb. In order to make use of the long-lived decay (17.3 My) for dating, the unknown half-life of the bound-state beta decay had to be measured first.
The complex experiment was carried out at GSI/FAIR using the ESR storage ring. It involved the production of 205Tl from a stable 206Pb beam as well as accumulation and storage of high intensities in the ESR. Finally, the ratio of mother-to-daughter nuclei after different waiting times was measured using non-destructive Schottky detectors and enabled the evaluation of a half-life of 291 days for this exotic decay.
