摘要
利用能量为44MeV的13C束流,通过重离子熔合蒸发反应82Se(13C,4n)91Zr布居了稳定核91Zr的高自旋态.基于γ-γ符合关系扩展了91Zr21/2+同核异能态上的能级纲图,根据实验提取的γ跃迁的角分布系数对部分能级的自旋进行了指认.前人对21/2+同核异能态下正负宇称能级已指认为质子在π(p1/2,g9/2)轨道的激发耦合价中子vd5/2;在π(f5/2,p3/2,p1/2,g9/2)和v(d5/2,s1/2,d3/2,g7/2,h11/2)空间内,经过系统性的分析和比较91Zr邻近核高自旋态能级结构,指出同核异能态上正宇称态激发机制依次为质子跨越38子壳π(f5/2,p3/2)→πp1/2激发和中子跨越50闭壳vg9/2→vd5/2激发,同核异能态上负宇称态可能涉及质子跨越38子壳π(f5/2,p3/2)→πg9/2激发与价中子vd5/2→vh11/2激发的竞争.
High spin states of stable nucleus 91Zr have been studied with the 82Se（13C, 4n）91Zr fusion evaporation reaction at an incident beam energy of 44 MeV. Based on γ-γ, coincidence relationships and ADO ratios, the level scheme of 91Zr above the 21/2＋ isomer has been extended and the spins of partial states have been assigned. It has been shown that the low-lying levels below the 21/2＋ isomer are dominated by the proton excitations within the π（p1/2, g9/2） shell model orbitals. According to systematic analysis and comparison with neighboring nuclei, the positive-parity states above the 21/2＋ isomer can be understood as the proton excitations within the π（f5/2, P3/2, Pl/2） shell model orbitals and one neutron excitation across the N=50 shell gap （vg9/2--~vds/2）, the negative levels above the 21/2＋ isomer might concern competition between one proton excitation across the Z=38 shell gap （n（fs/2, p3/2）→（f5/2） and the neutron excitation within （vds/2, vhw2） shell model orbitals.
出处
《中国科学：物理学、力学、天文学》
CSCD
北大核心
2012年第3期249-258,共10页
Scientia Sinica Physica,Mechanica & Astronomica
基金
国家自然科学基金资助项目(批准号:10825522,11175217)
关键词
高自旋态
能级纲图
组态
high spin state, level scheme, configuration
