Masses and Beta-Decay Studies of Neutron-Rich Nuclei using the X-Array and Gammasphere

Conference · Wed Dec 04 00:00:00 EST 2019

DOI:https://doi.org/10.1051/epjconf/201922301028· OSTI ID:1595781

Kondev, F. G.; Hartley, D. J.; Orford, R.; Clark, J. A.; Savard, G.; Auranen, K.; Ayangeakaa, A. D.; Bottoni, S.; Carpenter, M. P.; Copp, P.; Hoffman, C. R.; Lauritsen, T.; Seweryniak, D.; Stolze, S.; Wu, J.; Kay, B. P.; Orford, R.; Li, J.; Sethi, J.; Zhu, S.

Properties of neutron-rich nuclei in the A˜160 region are important for achieving a better understanding of the nuclear structure in this region where little is known owing to diffculties in the production of these nuclei at the present nuclear physics facilities. These properties are essential ingredients in the interpretation of the rareearth peak at A˜160 in the r process abundance distribution, since theoretical models are sensitive to nuclear structure input. Predicated on these ideas, we have initiated a new experimental program at Argonne National Laboratory. During the first experiment, beams from the Californium Rare Isotope Breeder Upgrade radioactive beam facility were used in conjunction with the SATURN decay station and the X-array. We focused initially on several odd-odd nuclei, where β decays of both the ground state and an excited isomer were investigated. Because of the spin difference, a variety of structures in the daughter nuclei were selectively populated and characterized based on their decay properties. Mass measurements using the Canadian Penning Trap aimed at establishing the excitation energy of the β-decaying isomers were also carried out. Evidence was found for a change in the single-particle structure, which in turn results in the formation of a sizable N=98 sub-shell gap at large deformation. Results from the first experimental campaign using the newly-commissioned β-decay station at Gammasphere are also presented.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science - Office of Nuclear Physics; National Science Foundation (NSF); USDOE National Nuclear Security Administration (NNSA) - Office of Defense Nuclear Nonproliferation - Nonproliferation and Verification R&D (NA-22)
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1595781
• Resource Relation: Conference: 4th International Conference on Nuclear Structure and Dynamics, 05/13/19 - 05/17/19, Venice, IT
• Country of Publication: United States
• Language: English