SuperCDMS 25 kg Experiment

对星系、超星系团、遥远的超新星和宇宙微波背景辐射的观测告诉我们，宇宙中约85%的物质不是由普通粒子组成的。破译这种暗物质的性质对宇宙学、天体物理学和高能粒子物理都是至关重要的。一个主要的假设是，它是由相互作用很弱的大质量粒子组成的，这些粒子是在大爆炸后不久产生的。如果WIMP是暗物质，那么它们在我们银河系中的存在可能是通过地面探测器中原子核的散射来检测到的。低温暗物质搜索(CDMS)合作开创了使用低温声子介导的探测器来探测WIMP在原子核上的罕见散射并将它们与背景区分开来的先河。这项强大的技术在明尼苏达州苏丹矿的地下深处进行，这是世界上最灵敏的WIMP搜索，预计到2007年底，他们的探测范围将增加8倍。这项提议要求为超级CDMS 25公斤实验提供资金，该实验将把WIMP暗物质的直接探测范围扩大两个数量级。这项合作将结合他们转移到SNOLAB的准备工作，以降低宇宙成因的中子水平，并继续运行苏丹设施的CDMS探测器。这项技术的发展将推动声子介导的探测器的极限，它的应用越来越广泛。该项目将扩大其在Soudan的公共推广计划，将其经验转移到SNOLAB，将继续参与K-12，与教师合作，并支持来自贫困背景的有前途的高中生。

Observations of galaxies, superclusters, distant supernovae and the cosmic microwave background radiation, tell us that ~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, and high-energy particle physics. A leading hypothesis is that it is comprised of Weakly Interacting Massive Particles, or WIMPs, that were produced moments after the Big Bang. If WIMPs are the dark matter, then their presence in our Milky Way may be detectable via scattering from atomic nuclei in a terrestrial detector. The Cryogenic Dark Matter Search (CDMS) Collaboration has pioneered the use of low temperature phonon-mediated detectors to detect the rare scattering of WIMPs on nuclei and to distinguish them from backgrounds. With this powerful technology, operating deep underground in the Soudan mine in Minnesota, this is the most sensitive WIMP search in the world, and their reach is projected to grow by factor of eight by the end of 2007.This proposal requests funding for the SuperCDMS 25 kg Experiment that will extend the direct-detection reach for WIMP dark matter by an additional two orders of magnitude. The collaboration will combine their preparation for moving to SNOLAB, to reduce the cosmogenic neutron level, with continued running of the CDMS detectors at the Soudan facility. The technical development will push the envelope of phonon-mediated detectors, which have increasing applications. The project will expand its public outreach program at Soudan, transfer its experience to SNOLAB, will continue their involvement in K-12, collaborate with teachers and support promising high school students from underserved backgrounds.