Using Fast Neutrons to Explore Nuclear Structure

肯塔基大学的核结构研究集中在核谱学、中子诱导反应和中子散射等相关课题上。这项工作的大部分将利用该大学加速器设施产生的快中子和该实验室独特的伽马射线和中子探测能力；与其他几个机构的同事的补充合作研究正在进行中，预计这些合作将继续下去。中子散射实验主要是为了探索近球形原子核中四极和八极核的多声子振动激发，研究磁偶极跃迁和电偶极跃迁在集体激发中的单独作用，定义质子和中子在集体模中的作用，以及了解核壳结构和核形状跃迁的本质。混合对称态的声子耦合激发作为一种新型的集体模，在弱变形核中的激发特性将受到高度重视。一个新的方向是使用更高能量的中子来产生最终的原子核，而带电粒子聚变-蒸发反应不容易获得这些原子核。用多普勒频移衰减法和伽马-伽马符合测量方法测定寿命将在许多此类研究中发挥关键作用，我们实验室已经为它们开发了方法学。中子散射研究有助于阐明中子激发与其他探测器之间的区别，这将补充集体激发的微观基础研究。将继续在其他领域进行精心挑选的研究，例如核天体物理学和轻核的性质，这些研究特别适合肯塔基大学加速器实验室的能力和设施。教育仍然是我们实验室所有活动的重要组成部分，并将努力为肯塔基大学核科学本科生、研究生和研究生教育提供良好的工作环境。

Research in nuclear structure at the University of Kentucky is focussed on related topics in nuclear spectroscopy, neutron-induced reactions, and neutron scattering. Most of this work will utilize fast neutrons produced at the University's accelerator facility and the unique gamma-ray and neutron detection capabilities of this laboratory; complementary, collaborative research with colleagues at several other institutions is in progress and these collaborations are expected to continue. Neutron scattering experiments are primarily oriented toward exploring multiphonon vibrational excitations of the quadrupole and octupole types in nearly spherical nuclei, examining the separate roles of magnetic and electric dipole transitions in collective excitations, defining the roles of protons and neutrons in collective modes, and understanding nuclear shell structure and the nature of nuclear shape transitions. The characterization of phonon-coupled excitations of mixed-symmetry states, a new type of collective mode, in weakly deformed nuclei will receive a high priority. A new direction is the use of higher-energy neutrons to produce final nuclei that are not readily accessible with charged-particle fusion-evaporation reactions. Lifetime determinations with the Doppler-shift attenuation method and gamma-gamma coincidence measurements, for which the methodologies have been developed in our laboratory, will play crucial roles in many of these studies. Neutron scattering studies, which aid in elucidating the differences between neutron excitation and other probes, will complement studies of the microscopic basis of collective excitations. Carefully selected studies in other areas, e.g., nuclear astrophysics and the properties of light nuclei, which are particularly appropriate to the capabilities and facilities at the University of Kentucky accelerator laboratory will be pursued. Education continues to be an important component of all activities in our laboratory, and efforts to provide an excellent working environment for undergraduate, graduate, and post-graduate education in nuclear science at the University of Kentucky will be made.