Particle Astrophysics at Yale: The LUX Dark Matter Search

这个奖项为耶鲁大学的研究小组提供资金，用于LUX-350暗物质实验。LUX-350有望大幅提高对弱相互作用大质量粒子（wimp）存在的灵敏度，这是对失踪暗物质本质的一个理论上有吸引力的解释。LUX-350是一个两相（液/气）氙实验，总液氙（LXe）质量为350 kg，基准质量为100 kg。LUX-350探测器利用LXe的许多功能来驱动背景下降。有源探测器体积允许完全重建事件能量沉积和位置。关键是，由于周围LXe的主动屏蔽，背景速率在基准体积中受到严重抑制，并随着LXe质量的增加而降低。LUX-350的集成将在SUSEL新装修的地面设施中进行，即位于Homestake的Sanford地下科学与工程实验室，然后再转移到地下。在LUX-350上，耶鲁大学负责氙净化系统、100千伏阴极高压系统、慢速控制电子设备和用于探测器校准的放射源操纵器。该小组还开发了一种使用溶解在LXe中的Kr-83原子校准LXe探测器的方法，并对LXe中核反冲的闪烁效率和电荷产率进行了新的测量。更广泛的影响：与LXe相关的技术的发展将在世界范围内使用贵重液体作为检测材料的越来越多的实验中得到应用。这些项目还将为研究生和本科生提供辐射探测、低温学和气体净化方面的技术培训。LXe在天体物理学、国土安全、医学成像以及快中子探测的伽马射线成像方面具有实际应用。

This award provides funds for this Yale University group to contribute to the LUX-350 dark matter experiment. LUX-350 promises substantially improved sensitivity to the existence of Weakly Interacting Massive Particles (WIMPs), a theoretically attractive explanation for the nature of the missing dark matter. LUX-350 is a two-phase (liquid/gas) xenon experiment, with a total liquid xenon (LXe) mass of 350 kg and a fiducial mass of 100 kg. The LUX-350 detector exploits a number of features of LXe to drive backgrounds down. The active detector volume permits the full reconstruction of event energy deposition and position. Crucially, the background rate is heavily suppressed in the fiducial volume due to the active shielding by the surrounding LXe, and decreases with increasing LXe mass. Integration of LUX-350 will take place at a newly renovated surface facility at SUSEL, the Sanford Underground Science and Engineering Laboratory at Homestake before moving underground.On LUX-350, Yale is responsible for the xenon purification system, the 100 kV cathode high voltage system, slow control electronics, and radioactive source manipulators for detector calibration. The group has also developed a method of calibrating LXe detectors using Kr-83 atoms dissolved in the LXe, and performed a new measurement of the scintillation efficiency and charge yield for nuclear recoils in LXe. Broader Impact: Development of technology related to LXe will find use in the increasing number of experiments worldwide using noble liquids as detection materials. These projects will also result in technical training in radiation detection, cryogenics, and gas purification for graduate and undergraduate students. LXe has practical applications to gamma ray imaging for astrophysics, Homeland Security, and medical imaging, as well as for fast neutron detection.