RUI: Experimental Studies of N=Z Nuclei Near 72Kr

在72Kr附近具有相同数目的中子和质子的原子核为原子核理论提供了有趣而重要的检验，因为它们可以提供关于中子-质子(NP)对相互作用的信息，并检验我们对原子核形状演化的理解。最近，NP配对提出了两种可能的结果：核子对断裂并与核的角动量对准的旋转频率的延迟，以及奇奇核N=Z的表观低能级密度。这项工作的主要焦点是收集、分析和解释奇奇核74Rb和88Y的低自旋态数据，这些数据鲜为人知或一无所知。这些实验将在阿贡国家实验室(ANL)进行，使用伽马球层阵列、中子探测器阵列和阿贡碎片质量分析仪(FMA)。这项工作的第二个重点是对72Kr核的研究，包括使用与FMA耦合的Gammasphere阵列进行的低自旋实验。这个实验的目的是观察和描述低激发能量和角动量下的状态，包括多年来一直难以捉摸的扁平带的预期延续。这项工作将在两名本科生研究助理的支持下完成，他们将有机会参与实验的建立，以及数据的收集和分析。

Nuclei with equal numbers of neutrons and protons near 72Kr provideinteresting and important tests of nuclear theory, as they can supply information onthe interaction of neutron-proton (np) pairs, and test our understanding of the evolutionof nuclear shape. Recently, two possible consequences of np pairing have been offered: adelay in the rotational frequency at which nucleon pairs break and align with theangular momentum of the core, and the apparent low level density of odd-odd N=Z nuclei.The primary focus of this work is the collection, analysis and interpretation of data onlow-spin states in the odd-odd nuclei 74Rb and 88Y, of which little or nothing is known. Theexperiments will be carried out at Argonne National Laboratory (ANL) using theGammasphere array, an array of neutron detectors, and the Argonne Fragment Mass Analyzer(FMA). A secondary focus of this work is on studies of the nucleus 72Kr,including a low-spin experiment using the Gammasphere array coupled to the FMA. The goal ofthis experiment is to observe and characterize the states at low excitationenergy and angular momentum, including the expected continuation of an oblate band thathas remained elusive through the years. This work will be done with the support oftwo undergraduate research assistants who will have the opportunity to participate in thesetup of experiments, and the collection and analysis of the data.