Supplement for LHe in Support of the LEGS Photonuclear Physics Program

詹姆斯麦迪逊大学的光子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（LEGS）进行一个项目。物理程序解决了核子和介子产生的自旋结构。该计划的核心是强极化氘化氢ICE （SPHICE）目标。这种独特的极化高清靶允许测量极化质子、中子和氘核的不对称性和绝对横截面。有了质子和氘核目标，人们可以同时测量中子和质子的可观测值，减少了系统不确定性的影响。LEGS项目正在进入最后阶段，它将首次提供对这些自旋观测的同步测量。除了低温极化靶外，实验还采用了超导，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用于SPHICE目标生产的高纯度HD。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，为他们提供了低温物理和真空技术的宝贵经验。这个低温设施在世界上是独一无二的。在学年的校园准备之后，学生将在2006年夏天在布鲁克海文国家实验室度过几个星期，以获得探测器开发，数据分析和仪器的经验。这样的校外体验在JMU很少见，可以让学生接触到来自世界各地的合作者。作为leg - spin合作项目的成员，JMU小组正在BNL与来自意大利、法国和德国的科学家一起工作。

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.