近代物理研究所超重核研究现状及计划

简单描述了超重核合成的历史与国际现状， 详细地介绍了近代物理研究所已经开展的研究工作及取得的成果， 并对近代物理研究所未来在超重核研究方面的研究计划进行了介绍。 The history and the international status of the super heavy nuclei synthesis are briefly described. The related research work carried out at the Institute of Modern Physics (IMP) has been reviewed. The prospect of the super heavy nuclei research at IMP has been introduced.     

145Tb的高自旋态能级纲图

利用能量为161—175MeV的³²S束流,通过反应¹¹⁸Sn(³²S,1p4n)产生了¹⁴⁵Tb的高自旋态.进行了γ射线的激发函数、γγt符合测量.首先建议了由24条能级和42条γ跃迁组成的¹⁴⁵Tb核的能级纲图,并指定了各条能级的自旋值及部分低位能级的宇称.用一个πh_11/2价质子与¹⁴⁴Gd核芯激发态的耦合定性地解释了¹⁴⁵Tb的一些低位激发态.     

82.7MeV 16O+27Al碰撞中类弹碎片和发射α粒子的符合测量

在82.7MeV ¹⁶O+²⁷Al反应的类弹碎片和发射α粒子的符合测量中, 得到了在速度平面上的类弹碎片C和α粒子符合的伽利略协变截面的等高图和符合关联角分布. 测到的关联α粒子在正角度区(与类弹产物在束流的同侧)主要来源于类弹发射; 在负大角区主要来源于类靶发射; 在负小角区主要是弹核¹⁶O碎裂的贡献. 提出了弹核碎裂后的余核在靶核作用下继续进行阻尼碰撞的反应机制的可能性. 同时也确定了单举DIC测量时强的碳碎片产额中, 来自DIC激发的¹⁶O发射α粒子的余核¹²C的贡献并不大.     

Electric-dipole transitions in ^165Er

High-spin states of ^165Er were studied using the ^160Gd（^9Be, 4n）reaction at beam energies of 42 and 45 MeV. The previously known bands based on the ν5/2^-[523] and ν5/2^＋[642] configurations have been extended to high-spin states. Electric-dipole transitions linking these two opposite parity bands were observed. Relatively large B（E1） values have been extracted experimentally and were attributed to octupole softness.     

Properties of the β-delayed proton decay of 146Ho

The proton-rich isotope 146Ho was produced via the fusion-evaporation reaction ^92Mo （^58Ni, 3p1n）. The β-delayed proton decay of 146Ho was studied by proton-γ coincidence measurements using a He-jet tape transport system. The γ-transitions in ^145Tb following the proton emissions were observed, and the β-delayed proton branching ratios to the final states in the grand-daughter nucleus ^145Tb were determined. According to the relative branching ratios, the ground-state spin of 146Ho has been proposed and the possible configuration discussed.     

双奇核中πi_(13/2)νi_(13/2)2-准粒子转动带旋称反转研究

利用重离子熔合蒸发反应和在束γ谱学实验方法研究了双奇核176,178Ir和182 Au的高自旋态结构 ,在这 3个双奇核中观测到了基于πi13 2 νi13 2 准粒子组态下的转动带 .以能级间隔系统学为判据 ,对184Au核中πi13 2 νi13 2 转动带能级自旋进行了指定 .指出176,178Ir和182 ,184Au 4个双奇核的πi13 2 νi13 2 转动带在低自旋区均出现旋称反转 .对πi13 2 νi13 2 转动带旋称反转现象进行了定性的讨论 .用推转壳模型对πh9 2 νi13 2 带和πi13 2 νi13 2 带能级结构进行了理论研究 ,发现当采用形变和对力自洽计算后 ,从理论上可以定性地解释两个半退耦带出现的旋称反转现象     

一个可能的117Cs核πh11/2带的观测

在对²⁸Si轰击⁹²Mo靶反应进行的在束γ测量中,观测到一个全新的转动带,通过对其跃迁强度、结构特性的分析,认定它可能是建立在¹¹⁷Cs核的h_11/2质子能级上的转动带.     

179,183Au核1/2[660]转动带结构研究

通过重离子核反应¹⁴⁹Sm(³⁵Cl,5n)¹⁷⁹Au和¹⁵⁹Tb(²⁹Si,5n)¹⁸³Au研究了^179,183Au的高自旋态. 首次建立了¹⁷⁹Au的1/2[660](πi_13/2)转动带和¹⁸³Au的πi_13/2转动带的能量非优先带. 结合已有的实验数据, 讨论了奇A Au核中1/2[660](πi_13/2)转动带的形变随中子数的变化.     

Shell Evolution Study for New Magic Number N =32 via Isochronous Mass Spectrometry

Recent results and progress of mass measurements of neutron-rich nuclei utilizing Isochronous Mass Spectrometry (IMS) based on the HIRFL-CSR complex at Lanzhou are reported. The nuclei of interest were produced through projectile fragmentation of primary 86Kr ions at a realistic energy of 460.65 MeV/u. After in-flight separation by the fragment separator RIBLL2, the fragments were injected and stored in the experimental storage ring CSRe, and their masses were determined from measurements of their revolution times. The re-determined masses were compared and evaluated with other mass measurements, and the impact of these evaluated masses on the shell evolution study is discussed.     

Observation of Three-Quasiparticle Doublet Bands in ^123I： Possible Evidence of Chirality

A new band in the odd proton nucleus ^123I is identified via in-beam γ-ray spectroscopy using the ^14N＋^116Cd reaction. This band shows up as doublets with the previously assigned π97/2 （vh11/2）^2 band. Possible configurations of the new band are discussed in the framework of the cranked shell model and the geometrical model It is argued that the new band might be a chiral partner of the previously known πg9/2 （vh11/2）2 band.