Physics Letters B (Aug 2017)
New short-lived isotope 223Np and the absence of the Z = 92 subshell closure near N = 126
- M.D. Sun,
- Z. Liu,
- T.H. Huang,
- W.Q. Zhang,
- J.G. Wang,
- X.Y. Liu,
- B. Ding,
- Z.G. Gan,
- L. Ma,
- H.B. Yang,
- Z.Y. Zhang,
- L. Yu,
- J. Jiang,
- K.L. Wang,
- Y.S. Wang,
- M.L. Liu,
- Z.H. Li,
- J. Li,
- X. Wang,
- H.Y. Lu,
- C.J. Lin,
- L.J. Sun,
- N.R. Ma,
- C.X. Yuan,
- W. Zuo,
- H.S. Xu,
- X.H. Zhou,
- G.Q. Xiao,
- C. Qi,
- F.S. Zhang
Affiliations
- M.D. Sun
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China; Lanzhou University, Lanzhou 730000, China
- Z. Liu
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; Corresponding author.
- T.H. Huang
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- W.Q. Zhang
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- J.G. Wang
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- X.Y. Liu
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
- B. Ding
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- Z.G. Gan
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- L. Ma
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- H.B. Yang
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- Z.Y. Zhang
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- L. Yu
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- J. Jiang
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
- K.L. Wang
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
- Y.S. Wang
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- M.L. Liu
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- Z.H. Li
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
- J. Li
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
- X. Wang
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
- H.Y. Lu
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
- C.J. Lin
- China Institute of Atomic Energy, P.O. Box 275(10), Beijing 102413, China
- L.J. Sun
- China Institute of Atomic Energy, P.O. Box 275(10), Beijing 102413, China
- N.R. Ma
- China Institute of Atomic Energy, P.O. Box 275(10), Beijing 102413, China
- C.X. Yuan
- Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-Sen University, Zhuhai, 519082, Guangdong, China
- W. Zuo
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- H.S. Xu
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- X.H. Zhou
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- G.Q. Xiao
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- C. Qi
- KTH Royal Institute of Technology, Albanova University Center, SE-10691, Stockholm, Sweden
- F.S. Zhang
- Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875, China; Beijing Radiation Center, Beijing 100875, China
- Journal volume & issue
-
Vol. 771
pp. 303 – 308
Abstract
The N=130 short-lived isotope 223Np was produced as evaporation residue (ER) in the fusion reaction 40Ar + 187Re at the gas-filled recoil separator Spectrometer for Heavy Atom and Nuclear Structure (SHANS). It was identified through temporal and spatial correlations with α decays of 215Ac and/or 211Fr, the third and fourth members of the α-decay chain starting from 223Np. The pileup signals of ER(223Np)–α(223Np)–α(219Pa) were resolved by using the digital pulse processing technique. An α decay with half-life of T1/2=2.15(52100) μs and energy of Eα=9477(44)keV was attributed to 223Np. Spin and parity of 9/2− were tentatively proposed for the ground state of 223Np by combining the reduced α-decay width and large-scale shell-model calculations. This assignment together with the proton separation energy disprove the existence of a Z=92 subshell closure. Keywords: New isotope, Short-lived α radioactivity, Proton separation energy, Subshell closure
