Supplement for LHe in Support of the LEGS Photonuclear Physics Program

LHe 补充品支持 LEGS 光核物理项目

• 批准号: 0550097
• 负责人: C. Steven Whisnant
• 金额: --
• 依托单位: James Madison University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0550097&HistoricalAwards=false
• 关键词: Supplement; LHe; Support; LEGS; Photonuclear

The photonuclear physics group at James Madison University is conducting a program at the Laser Electron Gamma Source (LEGS) located at Brookhaven National Laboratory. The physics program addresses the spin structure of the nucleon and pion production. Central to this program is the Strongly Polarized Hydrogen deuteride ICE (SPHICE) target. This unique, polarized HD target permits measurement of asymmetries and absolute cross sections on the polarized proton, neutron, and deuteron. With proton and deuteron targets, one can measure observables on the neutron and the proton at the same time, reducing effects from systematic uncertainties. The LEGS program, which is entering its final phase, will provide the first such simultaneous measurements of these spin observables. In addition to the cryogenic polarized target, the experiment employs a superconducting, requiring a large consumption of liquid helium. On-campus efforts at James Madison University focus on the distillation of high purity HD for SPHICE target production. Student involvement in operating, developing control and monitoring hardware and software, and optimizing the performance of this facility provides them with valuable experience in low temperature physics and vacuum techniques. This low temperature facility is unique in the world. After preparation on-campus during the academic year, students will spend several weeks during the summer of 2006 at Brookhaven National Laboratory to gain experience in the detector development, data analysis, and instrumentation. Such an off-campus experience, rare at JMU, provides contact with collaborators from around the world. As members of the LEGS-Spin Collaboration, the JMU group is working at BNL with scientists from Italy, France and Germany.

詹姆斯·麦迪逊大学的光核物理小组正在布鲁克海文国家实验室的激光电子伽马源(LEGES)进行一项计划。这个物理计划解决了核子和介子产生的自旋结构问题。该计划的核心是强极化的氢化氢冰(SPHICE)靶。这种独特的极化HD靶可以测量极化质子、中子和氘的不对称性和绝对截面。有了质子和质子靶，就可以同时测量中子和质子的可观测性，减少系统不确定性的影响。LEGS计划正在进入最后阶段，它将提供这些自旋可观测到的第一次这样的同步测量。除了低温极化目标外，该实验还使用了超导材料，这需要大量的液氦消耗。詹姆斯·麦迪逊大学的校园工作重点是蒸馏高纯度高清，以实现SPHICE目标生产。学生参与操作、开发控制和监控硬件和软件，并优化该设施的性能，为他们提供了在低温物理和真空技术方面的宝贵经验。这种低温设施在世界上是独一无二的。在本学年的校园准备之后，学生们将在2006年夏天在布鲁克海文国家实验室呆上几周，以获得探测器开发、数据分析和仪器设备方面的经验。这样的校外体验在JMU是罕见的，它提供了与来自世界各地的合作者的联系。作为腿部旋转合作项目的成员，JMU团队正在BNL与来自意大利、法国和德国的科学家合作。