^(68)Zn核的高自旋结构研究  

High-spin States of^(68)Zn

作　　者：周振翔 罗迪雯 徐川[1] 吴鸿毅[1,2] 华辉 郑云[2] 李聪博[2] 吴晓光[2] 李天晓[2] 李广顺 李智焕[1] 李湘庆[1] 林杰[1] 郭成宇 郑敏 赵子豪 黎健宏 徐君宏 贾子豪 张集智 倪磊 张思洋 周小红 柳敏良[3] 贺创业[2] 刘伏龙[2] 王守宇 王硕[4] 孙大鹏[4] ZHOU Zhenxiang;LUO Diwen;XU Chuan;WU Hongyi;HUA Hui;ZHENG Yun;LI Congbo;WU Xiaoguang;LI Tianxiao;LI Guangshun;LI Zhihuan;LI Xiangqing;LIN Jie;GUO Chengyu;ZHENG Min;ZHAO Zihao;LI Jianhong;XU Junhong;JIA Zihao;ZHANG Jizhi;NI Lei;ZHANG Siyang;ZHOU Xiaohong;LIU Minliang;HE Chuangye;LIU Fulong;WANG Shouyu;WANG Shuo;SUN Dapeng(School of Physics,State Key Laboratory of Nuclear Physics and Technology,Peking University,Beijing 100871,China;China Institute of Atomic Energy,Beijing 102413,China;Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,China;Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment,School of Space Science and Physics,Institute of Space Sciences,Shandong University,Weihai 264209,China)

机构地区：[1]北京大学物理学院,核物理与核技术国家重点实验室,北京100871 [2]中国原子能科学研究院,北京102413 [3]中国科学院近代物理研究所,甘肃兰州730000 [4]山东大学山东省光学天文与日地空间环境重点实验室,空间科学与物理学院,空间科学研究院,山东威海264209

出　　处：《原子能科学技术》2024年第12期2445-2451,共7页Atomic Energy Science and Technology

基　　金：国家自然科学基金(12035001);国家重点研发计划(2022YFA1602302)。

摘　　要：北京大学实验核物理研究组在中国原子能科学研究院的HI-13串列加速器上通过重离子熔合蒸发反应对70质量区^(68)Zn核的高自旋结构开展了实验研究,建立了其能级纲图,极大拓展了^(68)Zn高自旋态能级结构,将其转晕带的最高自旋由8ℏ拓展至了14ℏ,首次观察到^(68)Zn核完整的第1个带交叉。E-GOS图表明,随着自旋的增加,^(68)Zn的集体运动由振动逐渐向转动演化。使用Total Routhian Surfaces模型对实验结果进行了分析,结果显示,实验观察到的^(68)Zn核第1个带交叉来自1对1g_(9/2)中子的顺排,1g_(9/2)质子对的顺排将发生在更高的转动频率处。TRS计算的偶-偶Zn核基态形变随中子的演化显示了N=40次闭壳的存在。For the nuclei in the A≈70 mass region,due to the large subshell gaps around Fermi surfaces in the single-particle spectra at prolate and/or oblate deformation,they exhibit rich and varied shaperelated phenomena,such as rapid shape transition,shape coexistence,and triaxiality,and have been the focus of theoretical and experimental investigations in recent years.High-spin studies of these nuclei can give us a straightforward interpretation in terms of the interplay between the single-particle and collective degrees of freedom.Here,it is reported that an experimental investigation on the high-spin properties of^(68)Zn via the ^(7)Li(^(64)Ni,p2n)^(68)Zn fusion-evaporation reaction at a beam energy of 34 MeV,which was performed in the HI-13 tandem facility of the China Institute of Atomic Energy by Peking University Experimental Nuclear Physics Group.The 64Ni target with a thickness of 0.99 mg/cm^(2) on 14.9 mg/cm^(2) Pb backing was used.The in-beam gamma-rays were detected by an array consisting of 6 segmented clover detectors and 24 high-purity germanium(HPGe)with bismuth germinate(BGO)anti-Compton suppressors.The digital data acquisition system GDDAQ based on XIA Pixie16 developed by our group was used for the detector array.Approximately 1.8×10^(9)γ-γcoincident events were detected.Aγ-γsymmetric matrix and aγ-γ-γcube were built from the coincidence events.The level scheme analysis was performed by using the RADWARE package.To obtain the directional correlations ofγ-ray deexciting oriented states(DCO)intensity ratios to determine the multipolarities ofγ-ray transitions,the detectors at 90.0°with respect to the beam direction were sorted against the detectors at 30.0°to produce a two-dimensional angular correlation matrix.The yrast band of^(68)Zn is expanded from 8ℏto 14ℏ,allowing the observation of the first band crossing.The characteristics of E-GOS curve for the yrast sequence in^(68)Zn indicate that this nucleus may undergo an evolution from quasivibrational to quasirotational structure with i

关 键 词：高自旋 ^(68)Zn 熔合蒸发反应 在束伽马谱学 壳结构 形变 

分 类 号：TL11[核科学技术—核能科学] O571.2[理学—粒子物理与原子核物理]