RUI: Collaborative Research: Improved Limits from DRIFT and R&D Towards Improved Directionality and Sensitivity

RUI：协作研究：改进 DRIFT 和 R 的限制

• 批准号: 1407754
• 负责人: Daniel Snowden-Ifft
• 金额: $ 9.8万
• 依托单位: Occidental College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-15 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1407754&HistoricalAwards=false
• 关键词: RUI; Collaborative; Research; Improved; Limits

In this era of precision cosmology, measurements suggest that ordinary matter represents only a fraction of the total matter density in the Universe. The rest, whose effect we can see only gravitationally, is unknown in its nature and is termed Dark Matter. Particle physics models suggest that dark matter is composed of relic Weakly Interacting Massive Particles, or WIMPs, left over from the Big Bang. If WIMPs are the dark matter, then their presence in our galaxy may be detectable via scattering from atomic nuclei in detectors located deep underground to help reject backgrounds due to cosmic rays. Experimental efforts to detect WIMPs are extremely challenging due to the predicted small interaction probabilities and the existence of backgrounds that mimic the expected signal. Fortunately, a number of unique dark matter signatures exist that can be used to discriminate against backgrounds and decisively identify WIMP interactions. The largest and most robust signature is the predicted dependence of the WIMP flux on the Sun-Earth velocity through the Galaxy, yielding a sidereal modulation of the nuclear recoil direction in the laboratory. The Directional Recoil Identification From Tracks (DRIFT) dark matter experiment is a leader in the field of directional dark matter detection, with sensitivity to the powerful angular signature of nuclear recoils induced by WIMPs. The intellectual merit of this award resides in DRIFT's powerful capabilities being brought to bear on one of the most important questions in science today. The collaboration will be testing their next prototype detector, DRIFT-IIe, above ground at Occidental College. It features an inherently scalable design including a redesigned field cage, a texturized, thin-film cathode, a new, transparent wire readout which doubles the fiducial volume per readout, and a new every-wire data acquisition system which allows for lower noise and fiducialization in the detector plane. The potential of DRIFT's capabilities have promising applications to Homeland Security and double-beta decay experiments. Broader impacts of this work also include the training of a diverse set of undergraduate and graduate students (including underrepresented minorities) in increasingly rare small-scale experiments, giving them exposure to a wide range of research experience.

在这个精确宇宙学的时代，测量表明普通物质仅占宇宙总物质密度的一小部分。其余的物质，我们只能通过引力才能看到​​其影响，其性质未知，被称为暗物质。粒子物理模型表明，暗物质是由大爆炸遗留下来的弱相互作用大质量粒子（WIMP）组成的。如果 WIMP 是暗物质，那么它们在我们银河系中的存在可以通过位于地下深处的探测器中原子核的散射来探测到，以帮助排除宇宙射线造成的背景。由于预测的相互作用概率较小以及模拟预期信号的背景的存在，检测 WIMP 的实验工作极具挑战性。幸运的是，存在许多独特的暗物质特征，可用于区分背景并果断识别 WIMP 相互作用。最大、最稳健的特征是预测的 WIMP 通量对穿过银​​河系的日地速度的依赖性，从而在实验室中产生核反冲方向的恒星调制。轨道定向反冲识别 (DRIFT) 暗物质实验是定向暗物质探测领域的领先者，对 WIMP 引起的核反冲的强大角度特征非常敏感。该奖项的智力价值在于 DRIFT 强大的能力能够解决当今科学中最重要的问题之一。此次合作将在西方学院的地面上测试他们的下一个原型探测器 DRIFT-IIe。它具有固有的可扩展设计，包括重新设计的现场笼、纹理化薄膜阴极、新的透明线读数器（使每个读数的基准体积加倍）以及新的每线数据采集系统（可实现更低的噪声和基准化）在探测器平面上。 DRIFT 能力的潜力在国土安全和双 β 衰变实验中具有广阔的应用前景。这项工作的更广泛影响还包括在越来越罕见的小规模实验中对不同的本科生和研究生（包括代表性不足的少数群体）进行培训，让他们接触到广泛的研究经验。