Experimental Particle Cosmology at Case

项目编号：0801576INSTUTION：CASE WESTERN RESTUTUTION NSF项目：物理粒子ASTROPHYSICSPRINCIPAL调查员：Shutt，Thomas A.TITLE：CASE摘要的实验粒子宇宙学大量观测表明，宇宙由96%的不可见物质和能量组成。这些缺失成分的性质是物理学中最基本的谜团之一。看不见的暗物质的主要候选者？是大爆炸遗留下来的一种亚原子粒子，被称为弱相互作用大质量粒子(WIMP)。这种粒子也可以通过超对称性来预测，超对称性是一种受欢迎的新粒子模型。如果存在WIMP，那么它们也是我们银河系中的主要质量。尽管它们很少与常规物质相互作用，但通过它们与目标材料中的原子核的直接相互作用和随之而来的反冲，它们应该可以被地球上足够灵敏的探测器探测到。探测它们的主要挑战是将自然和宇宙产生的放射性减少高达10个数量级。大型地下氙气(LUX)合作组织了一个团队，实施一项雄心勃勃的计划，建造和操作一个总重量为300公斤、基准质量为100公斤的双相氙气探测器。大型探测器不仅需要设置改进的灵敏度极限，而且如果检测到信号，还需要在合理的时间内积累WIMP统计数据。LUX的设计强调使用简单的技术，特别是低温恒温器的设计和水屏障的使用，以尽可能快地扩大到大尺寸。因此，LUX计划将开发1-10吨暗物质探测器所需的技术。该奖项为案例小组履行其在LUX计划中的责任提供支持。该小组在LUX中起着至关重要的作用，负责低温恒温器和低温，协调CASE的集成和表面测试计划，从Xe中去除Kr，以及筛选释放Rn的部件。他们还有一个小而活跃的研发计划，旨在为下一阶段的超大规模实验所需的技术。在更广泛的影响中，这些技术本身可以进一步扩大规模，并应用于其他基础实验，如双贝塔衰变和太阳中微子。与其他粒子检测技术一样，位置灵敏度和粒子识别的新方法可能会产生新的医疗诊断技术，或应用于国土安全和核控制。

PROPOSAL NUMBER: 0801576INSTITUTION: Case Western ReserveNSF PROGRAM: PHY - PARTICLE ASTROPHYSICSPRINCIPAL INVESTIGATOR: Shutt, Thomas A.TITLE: Experimental particle cosmology at Case ABSTRACTA wealth of observations shows that the universe is composed of 96% invisible matter and energy. The nature of these missing components is one of the most fundamental mysteries in physics. The leading candidate for the invisible ?dark matter? is a subatomic particle left over from the big bang known as the Weakly Interacting Massive Particle (WIMP). Such particles are also predicted by supersymmetry, a favored class of new particle models. If WIMPs exist, they are also the dominant mass in our own Milky Way. Although they only rarely interact with conventional matter, they should nonetheless be detectable by sufficiently sensitive detectors on Earth through their direct interaction with, and the ensuing recoil of, nuclei in a target material. The primary challenge in detecting them is reducing natural and cosmogenic radioactivity by up to 10 orders of magnitude.The Large Underground Xenon (LUX) collaboration has assembled a team to carry out an ambitious program of constructing and operating a 300 kg total, 100 kg fiducial mass, dual-phase xenon detector. A large detector is required to not only set an improved sensitivity limit, but also to accumulate WIMP statistics in a reasonable time if a signal is detected. The LUX design emphasizes using simple technologies, in particular for the design of the cryostat and the use of a water shield, to scale to large size as rapidly as possible. Thus the LUX program will develop the technologies required for 1-10 ton dark matter detectors. This award provides support for the Case group to carry out its responsibilities in the LUX program. The group has a crucial role in LUX, being responsible for the cryostat and cryogenics, coordinating the integration and surface test program at Case, removing Kr from Xe, and screening parts for Rn emanation. They also have a small but active R&D program, aimed at technologies needed for a next-phase, very large-scale experiment.Among the broader impacts, the techniques themselves can be further scaled up and applied to other fundamental experiments such as double beta decay and solar neutrinos. As with other particle detection techniques, new methods of position sensitivity and particle discrimination may give rise to new medical diagnostic techniques, or applications to Homeland Security and nuclear control.