Low Energy Nuclear Physics Using the Princeton Cyclotron And Atomic Physics Techniques

[9420866]盖茨这个建议描述了一个主要基于普林斯顿回旋加速器使用的核物理程序。研究有三个主要目标：(1)研究核子-核子相互作用中的宇称非守恒，(2)寻找β衰变中的时间(T)反转非不变性，以及(3)研究对恒星结构和演化重要的反应。第一个和第二个目标完全基于原子物理技术，特别强调光泵浦和自旋交换，特别是在新型偏振3He光束的开发中。所提出的方法包括将极化的3He气体送入回旋加速器的现有发生器中。他们利用极化3He束研究核子-核子相互作用中的宇称不守恒问题，提出利用中子拾取反应在21Ne和19Ne中产生极化激发态。在这两种情况下，激发态都是宇称双重态的成员，由两个具有相同自旋但相反的对偶态组成。通过研究与偏振方向平行或反平行发射的伽马射线的不对称性，可以确定双重态内的宇称混合，从而提供有关核子之间存在有效宇称非守恒势的信息。研究人员还计划研究19Ne和35K β衰变中的T对称性，研究光对T反转非不变性的起源，这种现象迄今为止只在kaon系统中观察到。预期对D系数的预设限制会有一个数量级的改进。最后提出了对核天体物理学特别重要的几个反应的研究，以帮助了解爆炸核合成产生的观测丰度，并了解恒星的演化和结构。＊＊＊

9420866 Cates This proposal describes a nuclear physics program based largely on the use of the Princeton Cyclotron. There are three major goals to the research: (1) the investigation of parity non- conservation in nucleon-nucleon interactions,(2) searches for time (T) reversal non-invariance in beta decay, and (3) studies of reactions that are important to stellar structure and evolution. The firsts and second goal are based entirely on atomic physics techniques, with particular emphasis on optical pumping and spin exchange especially in the development of a novel polarized 3He beam. The proposed approach involves feeding polarized 3He gas into the existing inonizer of the cyclotron. Using the polarized 3He beam to study parity non-conservation in nucleon-nucleon interactions, they proposed to use neutron pick- up reactions to make polarized excited states in 21Ne and 19Ne. In both cases, the excited states are members of parity doublets comprising two closely spaced states with identical spin but opposite parities. By studying the asymmetries of gamma rays that are emitted wither parallel or anti-parallel to the polarization direction, it is possible to determine the parity mixing within the doublets, providing information on the effective parity non-conserving potential that exists between nucleons. The researchers also plan studies of T symmetry in the beta decay of 19Ne and 35K, studying light on the origin of T reversal non-invariance, a phenomena which thus far has only been observed in the kaon system. An order of magnitude improvement in the presets limits on the D coefficient are anticipated. Finally studies are proposed of several reactions of particular importance to nuclear astrophysics, to help epsilon the observed abundance's that result from explosive nucleosynthesis and understanding stellar evolution and structure. ***