RUI: Study of Photonuclear Physics with Polarized Beams and Targets

RUI：偏振光束和目标的光核物理研究

• 批准号: 0969159
• 负责人: C. Steven Whisnant
• 金额: $ 17.1万
• 依托单位: James Madison University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-15 至 2015-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0969159&HistoricalAwards=false
• 关键词: RUI; Study; Photonuclear; Physics; Polarized

This research project uses photonuclear reactions with polarized beams and targets to investigate the properties of the nucleon and nucleon resonances with Compton scattering and to study heavy nuclei through photofission. The group will measure the polarizabilities of the neutron with unprecedented accuracy, providing data for the first time on currently unknown quantities such as the nucleon spin polarizabilities. Such data permits precision tests of effective field theories, lattice quantum chromodynamics calculations and predictions of the standard model of nuclear physics. The comprehensive program of Compton scattering on the proton and neutron will extract the electromagnetic polarizabilities with high accuracy. The photofission studies with polarized photons exploits the strong variation of the beam asymmetry in the direct neutron production. The measurements provide a database for developing nuclear forensics and expand our understanding of this fundamental nuclear reaction. A collaboration has been assembled to measure beam-target asymmetries for meson production with polarized neutrons in a polarized HD target at Jefferson Lab. This group will purify the commercial grade HD gas for target production. Although the HD target is ideal for use in secondary beams, the JMU group will also, with collaborators from UVA, investigate the possibility of operating a dynamically polarized HD target for use in primary beams. This research program is integrated with the teaching mission of James Madison University (JMU) on multiple levels. It fits well with the new Applied Nuclear Physics (ANP) program currently under development at JMU. The synergy between this program and the ANP curriculium and our advanced laboratory experience will provide students with an expanded nuclear physics experience. More advanced undergraduates, particularly those with off-campus experience, will mentor younger students. The students bring their knowledge and enthusiasm to teaching middle school students in our annual demonstration show. Program continuity and solid student work habits are fostered by student communication through a variety of venues including technical notes on the web and paper presentation at conferences. This program will be integrated with the four NSF REU programs in the college to provide an immersive experience each summer. The on-campus opportunities in low-temperature systems and gas analysis are unique. Research and teaching at JMU are recognized as two facets of the same process. This integration of research and education continues to be one of the hallmarks of the highly rated undergraduate experience at JMU.

本研究项目利用偏振光束和靶的光核反应，研究核子和核子共振与康普顿散射的性质，并通过光裂变研究重核。该小组将以前所未有的精度测量中子的极化率，首次提供有关核子自旋极化率等目前未知量的数据。这些数据允许有效场论的精确测试，晶格量子色动力学计算和核物理标准模型的预测。质子和中子的康普顿散射综合计算程序可以高精度地提取电磁极化率。利用极化光子的光裂变研究利用了直接中子产生中束流不对称性的强烈变化。这些测量结果为发展核法医学提供了一个数据库，并扩大了我们对这一基本核反应的理解。一个合作已经组装测量介子生产与极化中子在极化HD目标在杰斐逊实验室的束靶不对称性。该小组将净化商业级HD气体用于目标生产。虽然HD目标非常适合用于次级光束，但JMU小组还将与UVA的合作者一起研究在初级光束中使用动态偏振HD目标的可能性。该研究计划与詹姆斯麦迪逊大学（JMU）的教学使命在多个层面上相结合。它与JMU目前正在开发的新应用核物理（ANP）计划非常吻合。该计划与ANP课程和我们先进的实验室经验之间的协同作用将为学生提供扩展的核物理经验。更先进的本科生，特别是那些有校外经验的，将指导年轻的学生。学生们把他们的知识和热情，以教学中学生在我们的年度示范表演。课程的连续性和扎实的学生工作习惯是由学生通过各种场所，包括在网络上的技术说明和会议上的论文演示交流培养。该计划将与学院的四个NSF REU计划相结合，每年夏天提供身临其境的体验。低温系统和气体分析的校园机会是独一无二的。JMU的研究和教学被认为是同一过程的两个方面。这种研究和教育的整合仍然是JMU高度评价的本科生经验的标志之一。