Masses and beta-Decay Spectroscopy of Neutron-Rich Odd-Odd Eu-160,Eu- 162 Nuclei: Evidence for a Subshell Gap with Large Deformation at N=98

作者：Hartley, D. J.^*; Kondev, F. G.; Orford, R.; Clark, J. A.; Savard, G.; Ayangeakaa, A. D.; Bottoni, S.; Buchinger, F.; Burkey, M. T.; Carpenter, M. P.; Copp, P.; Gorelov, D. A.; Hicks, K.; Hoffman, C. R.; Hu, C.; Janssens, R. V. F.; Klimes, J. W.; Lauritsen, T.; Sethi, J.; Seweryniak, D.; Sharma, K. S.; Zhang, H.; Zhu, S.; Zhu, Y.

来源：Physical Review Letters, 2018, 120(18): 182502.

DOI：10.1103/PhysRevLett.120.182502

• R-PROCESS NUCLEOSYNTHESIS
• RARE-EARTH ISOTOPES
• DATA SHEETS
• HIGH-SPIN
• CARIBU
• IDENTIFICATION
• SEPARATION
• FISSION

The structure of deformed neutron-rich nuclei in the rare-earth region is of significant interest for both the astrophysics and nuclear structure fields. At present, a complete explanation for the observed peak in the elemental abundances at A similar to 160 eludes astrophysicists, and models depend on accurate quantities, such as masses, lifetimes, and branching ratios of deformed neutron-rich nuclei in this region. Unusual nuclear structure effects are also observed, such as the unexpectedly low energies of the first 2(+) levels in some even-even nuclei at N = 98. In order to address these issues, mass and beta-decay spectroscopy measurements of the Eu-160(97) and Eu-162(99) nuclei were performed at the Californium Rare Isotope Breeder Upgrade radioactive beam facility at Argonne National Laboratory. Evidence for a gap in the single-particle neutron energies at N = 98 and for large deformation (beta(2) similar to 0.3) is discussed in relation to the unusual phenomena observed at this neutron number.

• 出版日期2018-5-4
• 单位中国人民解放军海军大连舰艇学院; 浙江大学; McGill