基于HI-13串列加速器在束γ终端原子核激发态寿命测量的核结构研究  

Nuclear Structure Studies Based on the Lifetime Measurements of Excited States in Nuclei at the in-beam γTerminal of HI-13 Tandem Accelerator

作　　者：郑云[1] 吴晓光[1] 李广生[1] 李聪博[1] 陈启明[1] 竺礼华[2,3] 贺创业[1] 郝昕[1,3] 王烈林[1] 姚顺和[1] 刘颖[1] 李立华[1] 汪金龙[1] 钟健[1] 周文奎[1] 邓利涛 朱宝吉 

机构地区：[1]中国原子能科学研究院,北京102413 [2]北京航空航天大学,北京100191 [3]深圳大学,深圳5180603

出　　处：《原子核物理评论》2016年第4期375-384,共10页Nuclear Physics Review

基　　金：国家自然科学基金资助项目(11305269;11375267;11475072;11405274;11205068;11175259)~~

摘　　要：利用在HI-13串列加速器的在束γ终端上建立的多普勒线移衰减法、反冲距离多普勒线移法和快时间延迟符合法等3种寿命测量方法,开展了原子核手征对称性、磁转动等核结构热点课题的研究工作。实验结果表明,^(130)Cs的伙伴带具有很好的手征特性,而^(106)Ag的候选带并非手征双带。根据测量的能级寿命提取的B(M1)值表明,^(106)Ag的正宇称晕带和^(107)Ag的正、负宇称晕带都具有典型的磁转动特性。此外,寿命测量数据还为解释和理解不同的同位素链中展现出的形状演化、形状共存、形状相变及临界点对称性等物理现象提供了有价值的实验证据。The significance and principle of lifetime measurements of excited states in nuclei are briefly described. By using the recoil-distance Doppler-shift method, the Doppler-shift attenuation method, and the fast-timing technique established at the in-beam γ terminal of HI-13 tandem accelerator, nuclear structure studies on topical subjects including chiral symmetries and magnetic rotation have been performed. Our experimental results indicate that ^（130）Cs shows better chiral characteristics, however, the two candidate bands of ^（106）Ag could not be a pair of chiral doublet bands. For magnetic rotation, the deduced B（M1） values deduced from the measured level lifetimes clearly demonstrate that the yrast positive-parity band in ^（106）Ag and both the yrast positiveand negative-parity bands in ^（107）Ag are magnetic rotation bands. In addition, our lifetime measurement data also provide valuable experimental evidences for the interpretation and understanding of the shape evolution, the shape coexistence, and the critical-point symmetries of shape phase transition in the different isotope chains.

关 键 词：能级寿命 核结构 多普勒线移衰减法 反冲距离多普勒线移法 快时间延迟符合法 

分 类 号：O571[理学—粒子物理与原子核物理]