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

使用普林斯顿回旋加速器和原子物理技术的低能核物理

• 批准号: 9420866
• 负责人: Gordon Cates
• 金额: $ 111.48万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-03-01 至 1998-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9420866&HistoricalAwards=false
• 关键词: Low; Energy; Nuclear; Physics; Using

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. ***

9420866本提案描述了一个主要基于普林斯顿回旋加速器使用的核物理计划。这项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)反转不变性；(3)研究对恒星结构和演化具有重要意义的反应。第一个和第二个目标完全基于原子物理技术，特别是在光抽运和自旋交换方面，特别是在开发一种新的偏振3He光束方面。所提出的方法包括将极化的3He气体送入回旋加速器现有的强子加速器。利用极化的~3He束流研究核子-核子相互作用中的宇称非守恒，他们提出利用中子拾取反应在21Ne和19Ne产生极化激发态。在这两种情况下，激发态都是由两个自旋相同但奇偶数相反的密集态组成的奇偶对的成员。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，从而提供关于核子之间存在的有效宇称非守恒势的信息。研究人员还计划对19Ne和35K的β衰变中的T对称性进行研究，研究T反转不变性的起源，这种现象到目前为止只在Kaon系统中观察到。预计D系数的预设限值将有数量级的改进。最后提出了对核天体物理特别重要的几个反应的研究，以帮助epsilon观测到的丰度是由爆炸性核合成产生的，并了解恒星的演化和结构。***