24-28 October 2022
La Thanh Hotel, Hanoi, Vietnam
Asia/Ho_Chi_Minh timezone
Thank you for your attendance!

Experimental studies of neutron-rich nuclei around N = 126 and beyond at KEK isotope separation system

27 Oct 2022, 11:10
20m
Online

Online

Speaker

Yutaka Watanabe (WNSC, IPNS, KEK)

Description

The nuclear properties such as lifetimes and masses of the neutron-rich nuclei are important parameters to investigate the astrophysical rapid neutron capture process (r-process). However, the difficulty in the production of those neutron-rich nuclei, especially at the waiting points on the neutron closed shell $N = 126$ and beyond, makes their experimental studies difficult. Therefore, the theoretical nuclear models play crucial roles in the simulation of the r-process nucleosynthesis. The experimental studies of those nuclear properties and nuclear structures provide significant inputs to those theoretical models to improve their predictability for the neutron-rich nuclei relevant to the formation of the r-abundance peak around $A = 195$ and actinide elements such as uranium and thorium.

We are developing KEK Isotope Separation System (KISS) at RIKEN RIBF facility to produce and separate those nuclei for their spectroscopic studies [1-3]. The multi-nucleon transfer (MNT) reactions between the $^{136}$Xe beam and the $^{198}$Pt target are employed to produce the nuclei around $N = 126$ [4-5]. The KISS consists of an argon-gas-cell-based laser ion source and an isotope separation on-line system, which allow to provide the mass and atomic number selectivity. The detector systems consisting of a multi-segmented gas counter [6-7] combined with high-purity germanium detectors and a Multi-Reflection Time-Of-Flight Mass Spectrograph (MRTOF-MS) make it possible to perform their beta-gamma spectroscopy, mass spectroscopy, and laser spectroscopy. Recently, we have also successfully measured masses in the actinide region using the MNT reactions between the $^{238}$U beam and the $^{198}$Pt target.

In this presentation, we will report the present status of the KISS including the recent experimental results of nuclear spectroscopy and the future plan.

[1] Y. Hirayama et al., Nucl. Instrum. and Methods B 353 (2015) 4.
[2] Y. Hirayama et al., Nucl. Instrum. and Methods B 376 (2016) 52.
[3] Y. Hirayama et al., Nucl. Instrum. and Methods B 463 (2020) 425.
[4] Y.H. Kim et al., EPJ Web of conferences 66 (2014) 03044.
[5] Y.X. Watanabe et al., Phys. Rev. Lett. 115 (2015) 172503.
[6] M. Mukai et al., Nulc. Instrum. and Methods A 884 (2018) 1.
[7] Y. Hirayama et al., Nucl. Instrum. and Methods A 997 (2021) 165152.

Please select a main topic related to your abstract Experimental Nuclear Physics for Astrophysics

Primary authors

Yutaka Watanabe (WNSC, IPNS, KEK) Prof. Yoshikazu Hirayama (WNSC, IPNS, KEK) Dr Momo Mukai (Nishina Center for Accelerator-Based Science, RIKEN) Dr Toshitaka Niwase (WNSC, IPNS, KEK) Dr Peter Schury (WNSC, IPNS, KEK) Dr Marco Rosenbusch (WNSC, IPNS, KEK) Prof. Michiharu Wada (WNSC, IPNS, KEK) Dr Shun Iimura (Department of Physics, Rikkyo University) Dr Sota Kimura (Nishina Center for Accelerator-Based Science, RIKEN) Dr Yuta Ito (Advanced Science Research Center, Japan Atomic Energy Agency) Dr Sun-Chan Jeong (WNSC, IPNS, KEK) Prof. Hiroari Miyatake (WNSC, IPNS, KEK) Dr Hironobu Ishiyama (Nishina Center for Accelerated-Based Science, RIKEN) Dr Jun Young Moon (Rare Isotope Science Project, Institute for Basic Science (IBS)) Dr Takashi Hashimoto (Rare Isotope Science Project, Institute for Basic Science (IBS)) Prof. Akihiro Taniguchi (Institute for Integrated Radiation and Nuclear Science, Kyoto University) Prof. Andrei Andreyev (Department of Physics, University of York)

Presentation Materials

There are no materials yet.