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

¹ Institut de Tècniques Energètiques (INTE), Universitat Politècnica de Catalunya (UPC), 08028 Barcelona, Spain.
² Instituto de Física Corpuscular (IFIC), CSIC-UV, E-46980 Paterna, Spain.
³ Institute for Nuclear Research (ATOMKI), 4026 Debrecen, Bem tér 18/c, Hungary.
⁴ University of Debrecen, 4032 Debrecen, Egyetem tér 1, Hungary.
⁵ Department of Physics, University of Jyväskylä, Finland.
⁶ Centro de Investigación en Física Nuclear y Espectroscopía de Neutrones (CEFNEN). Comisión Chilena de Energía Nuclear, Nueva Bilbao 12501, Las Condes, Santiago-Chile.
⁷ Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.
⁸ RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
⁹ Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA.
¹⁰ TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada.
¹¹ STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD, United Kingdom.
¹² School of Physics and Astronomy, The University of Edinburgh, Edinburgh EH9 3FD, United Kingdom.
¹³ Department of Physics and Astronomy, University of Victoria, Victoria, BC V8P 5C2, Canada.
¹⁴ Central Michigan University, Mt. Pleasant, MI 48859, USA.
¹⁵ Department of Physics, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan.
¹⁶ Center for Nuclear Study, The University of Tokyo, 2-1 Hirosawa, Wako, Saitama 351-0106, Japan.
¹⁷ Department of Physics, University of Liverpool, Liverpool L69 7ZE, United Kingdom.
¹⁸ Faculty of Physics, University of Warsaw, 02-093 Warsaw, Poland.
¹⁹ Department of Physics, the University of Hong Kong, Pokfulam Road, Hong Kong.
²⁰ Department of Physics and Astronomy, The University of British Columbia, Vancouver BC V6T 1Z1, Canada.
²¹ Heavy Ion Laboratory, University of Warsaw, Pasteura 5A, 02-093 Warsaw, Poland.
²² www.wiki.ed.ac.uk/display/BRIKEN/Home

^† atarisal@ific.uv.es
^* max.pallas@upc.edu

Published online: 26 May 2023

Abstract

Half-lifes (T_1/2) of exotic neutron-rich isotopes of Ba, La, Ce, Pr, and Nd were measured at the RIKEN Nishina Center. The experimental setup consisted of the BigRIPS in-flight separator for ion selection identification, the Advance Implantation Detector Array (AIDA) for ions and β detection, and the BRIKEN detector for neutron counting. Using this setup, 4 new T_1/2 have been measured for the first time, and 38 T_1/2 have been remeasured with improved precision in several cases. These new experimental data should help to constrain theoretical models for calculations of T_1/2. The status of the experimental analysis and preliminary results are provided in this contribution.