96Ru正宇称转晕带g因子测量与核结构研究

The nuclei in the A∼90 mass region present some interesting features of nuclear structure such as shape coexistence and shape transition, structure softness, alignments of protons and/or neutrons at high-j orbitals and competition between collectivity and quasi-particle alignment. The 96Ru with six valence protons and two valence neutrons outside 88Sr is suitable for the investigation of nuclear structure, especially proton and neutron alignments and their competition with collective motion, in the mass region of A~90. Nuclear g-factor is very sensitive to the proton and neutron alignments, and no g-factor measurements have been reported so far for the high spin states in 96Ru..The present proposal will use the fusion evaporation reaction to populate the yrast band in 96Ru and the transient magnetic field-ion implantation perturbed angular distribution method to determine the g-factors of individual states in the yrast band up to spin 16+. The measured g-factors can identify uniquely the proton and/or neutron alignments, reveal the competition between the proton and neutron alignments and the collective motion and its evolution with the increase of spin, explore the origin of angular momentum whether coming from quasi-particle alignment or from collective motion and examine the nuclear model.

A~90区核呈现形状共存和形状跃迁、结构强烈依赖中子和质子数、高角动量轨道中子或/与质子顺排及与集体转动竞争等核结构特性。核芯88Sr有6个价质子和2个价中子的96Ru（N=52，Z=44）适合于A~90区高自旋态核结构研究，特别是中子和质子顺排及它们与集体运动的竞争研究。原子核g-因子对质子和中子顺排非常灵敏，然而 96Ru高自旋态g-因子测量迄今未见报道。.本项目采用65Cu(35Cl,2p2n)96Ru熔合蒸发反应布居96Ru正宇称转晕(yrast)带，用瞬态场-离子注入扰动角分布方法测量该带到自旋16+的各个核态的g因子，确定质子或与中子顺排，了解集体转动与中子和质子顺排的竞争及其随自旋的演化，揭示核高自旋态核是从准粒子顺排的元激发还是从集体运动获得角动量，检验核结构理论模型。

A~90区核呈现形状共存和形状跃迁、结构强烈依赖中子和质子数、高角动量轨道中子或/与质子顺排及与集体转动竞争等核结构特性。由于质子中子g因子差异很大，g因子测量能够给出质子或中子顺排的直接证据。.本项目用熔合蒸发反应63Cu(37Cl,2p2n)96Ru布居96Ru高自旋态，用瞬态场-离子注入扰动角分布方法测量了正宇称转晕(yrast)带到自旋12+的各个核态的g因子，采用推转壳模型进行计算。实验结果及推转壳模型符合很好。在6+态及以下，原子核表现出集体转动性质，而在8+态以上出现回弯现象，主要是由质子顺排引起。