双奇核^(172)Re高自旋态实验研究  

Experimental Study of High-spin States in Odd-odd ^(172)Re

作　　者：张玉虎[1] 王华磊[1] 周小红[1] 柳敏良[1] M.Oshima Y.Toh M.Koizimi A.Osa A.Kimura Y.Hatsukawa T.Morikawa M.Nakamura M.Sugawara H.Kusakari T.Komatsubara K.Furuno 

机构地区：[1]中国科学院近代物理研究所,甘肃兰州730000 [2]Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195, Japan [3]Department of Physics, Kyushu University, Fukuoka 812-81, Japan [4]Chiba Institute of Technology, Narashino, Chiba 275-0023, Japan [5]Chiba University, Inage-ku, Chiba 263-8512, Japan [6]Institute of Physics and Tandem Accelerator Center, University of Tsukuba, Ibaraki 305-0006, Japan

出　　处：《原子核物理评论》2004年第4期320-323,共4页Nuclear Physics Review

基　　金：国家自然科学基金资助项目(10025525;10375077;10221003);国家重大基础研究发展规划资助项目(G2000077400);中国科学院基金资助项目~~

摘　　要：利用149Sm(27Al,4nγ)172Re反应布居了形变双奇核172Re的高自旋态,用12套带有BGO反康普顿抑制的高纯锗探测器阵列进行了在束γ实验测量,首次建立了172Re由3个转动带构成的高自旋态能级纲图.研究和讨论了3个转动带的结构特征,基于已有的高自旋态核结构知识并通过系统学比较和分析指出它们的准粒子组态分别为πh11/2 νi13/2,πh9/2 νi13/2和 π1/2-[541] ν1/2-[521].发现前两个转动带在自旋小于18时其转动能级呈现反常的旋称劈裂.High-spin states in the odd-odd^(172)Re have been investigated via the^(149)Sm(^(27)Al, 4nγ)^(172)Re reaction through excitation functions, X-γ and γ-γ coincidence measurements. A level scheme consisting of three rotational bands have been identified for the first time extending the high-spin studies of A≈160 odd-odd nuclei to the currently lightest rhenium isotope. The three bands have been assigned to be built on the πh_(11/2) νi_(13/2), πh_(9/2) νi_(13/2 ) and π1/2^-\ν1/2^-\ configurations according to their rotational properties in quasiparticle alignments, signature splitting, in-band B(M1)/B(E2) ratios, level spacing systematics, band crossing frequencies, as well as the existing knowledge in neighboring nuclei. Low-spin signature inversion has been confirmed in the first two bands due to observation of signature crossing at high-spin states.

关 键 词：高自旋态 形变双奇核 转动带 核结构 旋称劈裂 准粒子组态 能级纲图 首次 实验研究 抑制 

分 类 号：O571[理学—粒子物理与原子核物理] O572[理学—物理]