Detector Optimization for the SuperCDMS Experiment

几个观测天文学实验的结果表明，宇宙中大约85%的物质不是由普通粒子组成的。破译这种暗物质的本质对宇宙学、天体物理学、高能粒子物理学和我们对引力的理解都至关重要。一个主要的假设是暗物质是由弱相互作用的大质量粒子（wimp）组成的，wimp是一种超出粒子物理学标准模型的基本粒子，但在包括超对称在内的各种扩展中得到了预测。低温暗物质搜索（CDMS）合作，由美国国家科学基金会和美国能源部联合支持，率先使用基于超导薄膜传感器的低温声子介导探测器来区分核上这种wimp的罕见散射与其他背景事件。利用我们在苏丹矿井的强大技术，CDMS是目前（7月05日）世界上最敏感的WIMP搜索实验，以十倍的速度。由美国国家科学基金会提供的为期两年的资助将帮助支持圣克拉拉大学（SCU）小组继续积极参与苏丹CDMS实验的运作。这笔资金还将部分支持该小组继续研究用于低温探测器应用的超导传感器技术。这项工作包括以物理和技术为重点的超导铝合金传感器研究（可能对SuperCDMS和其他实验感兴趣），以及继续与CDMS合作者合作，将当前的钨基技术扩展到更大的SuperCDMS衬底。SCU小组将继续负责使用斯坦福大学现有的快速周转稀释冰箱设备，为CDMS合作提供超导薄膜的快速表征。在这两年的资助期内，未来传感器技术的评估将基于物理达到和提高设备制造产量的承诺。SCU小组包括私家侦探和两名本科生。该学院与附近院校，尤其是斯坦福大学（Stanford）和加州大学伯克利分校（UC Berkeley）的紧密联系，让该学院受益匪浅。这些机构的CDMS合作伙伴慷慨地为SCU小组提供了大量的低温和设备制造设备，他们的支持使SCU小组能够进行各种与CDMS相关的物理实验，否则SCU小组单独进行这些实验的成本过高。

Results from several observational astronomy experiments show that about 85% of the matter in the universe is not made of ordinary particles. Deciphering the nature of this dark matter would be of fundamental importance to cosmology, astrophysics, high-energy particle physics, and our understanding of gravity. A leading hypothesis is that dark matter is comprised of Weakly Interacting Massive Particles, or WIMPs, an elementary particle beyond the Standard Model of particle physics, but predicted in various extensions including Supersymmetry. The Cryogenic Dark Matter Search (CDMS) Collaboration, supported jointly by NSF and DOE, has pioneered the use of low temperature phonon-mediated detectors based on superconducting thin-film sensors to distinguish the rare scattering of such WIMPs on nuclei from other background events. Using our powerful technology in the Soudan mine, CDMS is currently (July 05) the most sensitive WIMP search experiment in the world, by a factor of ten. The two years of funding provided by this NSF award will help support the Santa Clara University (SCU) group continue its active participation in the operation of the CDMS experiment at Soudan. The funding will also partially support the group's continued work on superconducting sensor technologies for cryogenic detector applications. This work includes physics and technology-focused investigations of superconducting aluminum alloy sensors (potentially of interest for SuperCDMS and other experiments), as well as continued work with CDMS collaborators on feasible extensions of the current tungsten-based technology to larger substrates for SuperCDMS. The SCU group will continue to be responsible for using existing, fast turn-around, dilution-refrigerator facilities at Stanford University to provide the CDMS collaboration with rapid characterization of superconducting films. Evaluations of future sensor technologies based on both physics reach and promise for enhanced device fabrication yields will be ongoing throughout this two year funding period.The SCU group includes the P.I. and typically two undergraduates. The group benefits tremendously from its strong ties to groups at nearby institutions, particularly Stanford and UC Berkeley. CDMS collaborators at these institutions generously provide the SCU group access to their extensive cryogenic and device fabrication facilities and their support has allowed the SCU group to perform a variety of physics experiments related to CDMS and beyond, that otherwise would have been cost-prohibitive for the SCU group alone.