~(141)Nd激发态的在束γ谱学研究

通过1 3 0 Te(1 6O ,5nγ) 1 4 1 Nd反应布居了1 4 1 Nd的高自旋态能级 .对反应产生的在束γ射线进行了γ射线单谱和γ -γ符合测量 .建立了激发能达 76 1 4 .5keV的1 4 1 Nd能级纲图 ,新发现了 1 2条γ射线和 1 5个能级 .基于实验测量的γ跃迁各向异性 ,建议了1 4 1 Nd部分能级的自旋值 .用一个h1 1 2 价中子空穴与1 4 2 Nd核芯晕态的耦合可以定性地解释1 4 1 Nd的能级结构

~(141)Nd中的粒子-核芯耦合

通过~(130)Te(~(16)O,5nγ)~(141)Nd反应研究了~(141)Nd的高自旋态。建立了激发能达7614.5keV的~(141)Nd能级纲图,新发现了12条γ射线和15个能级。用粒子-振子模型和半经验壳模型分别计算了~(141)Nd的集体和单粒子激发的能级位置。根据计算的能级位置以及实验测量得到的γ跃迁强度和多极性信息,讨论了~(141)Nd激发态的能级结构。

~(130)Nd和~(140)Tb的EC/β~+衰变研究

利用能量为１７０ＭｅＶ左右的３６Ａｒ重离子束轰击９６Ｒｕ和１０６Ｃｄ浓缩同位素靶，分别生成缺中子同位素１３０Ｎｄ和１４０Ｔｂ．借助氦喷嘴带传输系统，用 Ｘ－γ和 γ－γ符合方法，分离鉴别了这两种核素，并进一步测定了它们的衰变性质．得到１３０ Ｎｄ的半衰期为（１３± ３）ｓ，首次建议了它的ＥＣ／β＋衰变纲图，推测了其子核１３０Ｐｒ的基态和低位能级的自旋宇称．修订了１４０Ｔｂ的原有极简单的ＥＣ／β＋衰变纲图并指认１４０Ｔｂ的基态自旋宇称为７＋．

~(143)Nd中高自旋同质异能态的识别与研究

利用能量为 80MeV的18O束流 ,通过130 Te( 18O ,5n)反应研究了143Nd的高自旋态能级结构 .基于γ γ延迟符合、γ射线的角分布及线性极化测量 ,首次发现了143Nd的一个半寿命为 ( 35± 8)ns,自旋和宇称为 4 9/ 2 + 的同质异能态 .用形变独立粒子模型探讨了此同质异能态的形成机制

Multi-quasiparticle gamma-band structure in neutron-deficient Ce and Nd isotopes

The newly developed multi-quasiparticle triaxial projected shell model approach is employed to study the high-spin band structures in neutron-deficient even-even Ce- and Nd-isotopes. It is observed that gamma-bands are built on each intrinsic configuration of the triaxial mean-field deformation. Due to the fact that a triaxial configuration is a superposition of several K-states, the projection from these states results in several low-lying bands originating from the same intrinsic configuration. This generalizes the well-known concept of the surface gamma-oscillation in deformed nuclei based on the ground-state to gamma-bands built on multi-quasiparticle configurations. This new feature provides an alternative explanation on the observation of two I = 10 aligning states in Ce-134 and both exhibiting a neutron character. (C) 2009 Elsevier B.V. All rights reserved.

2.6 s isomer of Nd-129

Nd-129 was produced by irradiation of an enriched target of Ru-96 with a Ar-36 beam and studied by using a helium-jet fast tape transport system in combination with X-gamma and gamma-gamma coincidence measurements. A 2.6s isomer of Nd-129 was observed for the first time and tentatively proposed to be the configuration of 1/2[411].

Two-quasiparticle K-isomeric states in strongly deformed neutron-rich Nd and Sm isotopes: a projected shell-model analysis

Motivated by recent spectroscopy data from fission experiments, we apply the projected shell model to study systematically the structure of strongly deformed, neutron-rich, even-even Nd and Sm isotopes with neutron number from 94 to 100. We perform calculations for rotational bands up to spin I = 20 and analyze the band structure of low-lying states with quasiparticle excitations, with emphasis given to rotational bands based on various negative-parity two-quasiparticle (2-qp) isomers. Experimentally known isomers in these isotopes are described well. The calculations further predict proton 2-qp bands based on a 5(-) and a 7(-) isomer and neutron 2-qp bands based on a 4(-) and an 8(-) isomer. The properties for the yrast line are discussed, and quantities to test the predictions are suggested for future experiment.