Ponente
Descripción
The synthesis heavy elements, such as gold and uranium, remains one of the most profound mysteries in astrophysics. These elements are believed to form through rapid neutron capture process (r-process) in extreme astrophysical environments. To better understand this process, it is crucial to study the structure and properties of very neutron-rich nuclei, particularly their beta-decay half-lives and first excited states, in the vicinity of the neutron magic number N=126 and below.
In this proposal, more than 90 beta-decay half-lives, including $^{201}$Re and possibly $^{200}$W, will be measured for the first time using the fragmentation of $^{208}$Pb. The beta-counting system WAS3ABi, in conjunction with the new gamma-ray spectrometer, will be employed for these measurements. Additionally, systematic studies of first excited states will be conducted via beta-gamma and the investigation of possible isomeric states. The experimental results will be incorporated into r-process network calculations to assess their impact on elemental abundances in solar, metal-poor stars [1], and meteorites [2].
[1] A. Alencastro et al., arXiv: 2412.00195c1 (2024), Submitted to Astro. Astrophys.
[2] T. Yokoyama, R, Walker, Review in Mineralogy & Geochemistry Vol. 81 pp. 107-160 (2016).
