21-23 March 2022
Europe/Madrid timezone

Study of beta decay properties for Pr to Nd nuclei (A~160) relevant for the formation of the r-process rare-earth peak

22 Mar 2022, 10:45
Red Temática de Física Nuclear (FNUC) Red FNUC (Red Temática de Física Nuclear)


Max Pallàs Solís (Universitat Politècnica de Catalunya (UPC))


Around half of the nuclei heavier than iron are created via the rapid neutron capture process (r-process). For nuclear masses A>100, there are two main peaks in the r-process elemental solar system abundances, located at A~130 and A~195, which are associated with the neutron shell closure during the (n,γ)→(γ,n) equilibrium. In contrast, the rare-earth peak (REP) is a small - but clear - peak around mass A=160, which originates from the freeze-out during the late phases after neutron exhaustion. The formation of the REP offers a unique probe for the study of the late-time conditions on the r-process site. According to theoretical models and sensitivity studies, half-lives (T1/2) and beta-delayed neutron emission probabilities (Pn) of very neutron-rich nuclei for 55< Z<64 are the most influential ones on the formation of the REP [1,2].
The BRIKEN project [3,4], launched in 2016 at the RIBF in the RIKEN Nishina Center, aims to measure beta-decay properties for a large number of nuclei on the path of the r-process. Accordingly, T1/2 and Pn-values for the most influential nuclei to the REP formation from Ba to Eu (A~160) have been measured for the first time with BRIKEN. In this work, the measurements of T1/2 and beta-delayed neutron branching probabilities (P1n) for several Pr and Nd isotopes in the mass region A~160 will be discussed. Preliminary experimental results on P1n-values will be presented for the first time.

[1] M. R. Mumpower et al. Phys. Rev. C 85, 045801 (2012).
[2] A. Arcones and G. Martinez Pinedo, Phys. Rev. C 83, 045809 (2011)
[3] J.L. Tain et. al, Acta physica polonica B, 49(03) (2018) 417–428.
[4] A. Tolosa-Delgado and et. al, NIM A 925 (2019) 133 – 147

Primary authors

Max Pallàs Solís (Universitat Politècnica de Catalunya (UPC)) Ariel Tarifeño-Saldivia (Instituto de Física Corpuscular (IFIC)) Dr. G. G. Kiss (Insitute for Nuclear Research (Atomki)) Jose Luis Tain (Instituto de Física Corpuscular (IFIC)) Nil Mont-Geli (Institut de Tècniques Energètiques (INTE), Universitat Politècnica de Catalunya (UPC)) Álvaro Tolosa-Delgado (University of Jyväskylä, Department of Physics) A. Vitéz-Sveiczer (Institute for Nuclear Research (Atomki)) BRIKEN collaboration

Presentation Materials

Your browser is out of date!

Update your browser to view this website correctly. Update my browser now