New short-lived isotope Np-223 and the absence of the Z=92 subshell closure near N=126
New short-lived isotope Np-223 and the absence of the Z=92 subshell closure near N=126
复制标题
新的短寿命同位素 Np-223 和 N=126 附近 Z=92 亚壳封闭的缺失
DOI：
10.1016/j.physletb.2017.03.074
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发表时间：
2017
影响因子：
4.4
通讯作者：
Zhou X. H.
中科院分区：
文献类型：
--
作者：
Sun M. D.;Liu Z.;Huang T. H.;Zhang W. Q.;Wang J. G.;Liu X. Y.;Ding B.;Gan Z. G.;Ma L.;Yang H. B.;Zhang Z. Y.;Yu L.;Jiang J.;Wang K. L.;Wang Y. S.;Liu M. L.;Li Z. H.;Li J.;Wang X.;Lu H. Y.;Lin C. J.;Sun L. J.;Ma N. R.;Yuan C. X.;Zuo W.;Xu H. S.;Zhou X. H.
在充气反冲分离器重原子与核结构能谱仪(SHANS)上，在40Ar+187Re聚变反应中产生N=130短寿命同位素223Np作为蒸发残留物(ER)。它是通过与215Ac和/或211Fr的α衰变的时间和空间相关性来确定的，215Ac和/或211Fr是从223Np开始的α衰变链的第三和第四成员。利用数字脉冲处理技术对ER(223nP)-α(223nP)-α(219pA)的堆积信号进行了解析。α衰变的半衰期T1/2=2.15(52 10 0)μS，能量Eα=9477(44)keV。结合约化−衰变宽度和大规模壳模型计算，初步提出了223Np基态的自旋和宇称为9/2α。这一指定与质子分离能一起证明了Z=92亚壳层闭合的存在。
The N= 130 short-lived isotope 223 Np was produced as evaporation residue (ER) in the fusion reaction 40 Ar+ 187 Re 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 215 Ac and/or 211 Fr, the third and fourth members of the α-decay chain starting from 223 Np. The pileup signals of ER (223 Np)–α (223 Np)–α (219 Pa) were resolved by using the digital pulse processing technique. An α decay with half-life of T 1/2= 2.15 (52 100) μs and energy of E α= 9477 (44) keV was attributed to 223 Np. Spin and parity of 9/2− were tentatively proposed for the ground state of 223 Np 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.