RUI: The DRIFT Directional Search for Dark Matter with Spin-Dependent Couplings

在这个精密宇宙学的时代，测量表明，普通物质只占宇宙总物质密度的一小部分。其余的似乎是黑暗的，我们只能从引力的角度看到它们的影响。粒子物理模型表明，暗物质是由大爆炸遗留下来的残余弱相互作用大质量粒子(WIMP)组成的。小的相互作用概率和模仿预期暗物质信号的大背景阻碍了直接探测WIMP的努力。幸运的是，存在一些独特的暗物质信号，可以用来区分背景并决定性地识别WIMP相互作用。根据太阳-地球系统穿过银河系时WIMP通量的预测行为，这些信号中最大和最强大的是实验室框架中核反冲方向的昼夜调制。这一提议的智力价值在于从径迹(漂移)中识别方向反冲实验的独特和强大的能力，该实验被用于解决当今科学中最重要的问题之一。该奖项提供资金支持该集团，并提供一个新的气体系统与CS2-CF4混合物一起运行，以及用于信任化漂移和用这样的系统改造现有漂移探测器的研发。这项工作的更广泛影响包括在越来越罕见的小规模实验中对本科生进行培训，让他们接触到广泛的硬件和软件经验。最后，漂移探测器技术在轴子搜索、国土安全和双β衰变实验中有很好的应用前景。

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 only see gravitationally, appears to be dark. Particle physics models suggest that dark matter is composed of relic weakly interacting massive particles (WIMPs) left over from the Big Bang. Efforts to directly detect WIMPs are hampered by small interaction probabilities and large backgrounds that mimic expected dark matter signals. 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 of these signatures, based on the predicted behavior of the WIMP flux as the Sun-Earth system moves through the galaxy, is a day-night modulation of nuclear recoil directions in the lab frame. The intellectual merit of this proposal resides in the Directional Recoil Identification From Tracks (DRIFT) Experiment's unique and powerful capabilities being brought to bear on one of the most important questions in science today. This award provides funds to support this group and to provide a new gas system to run with CS2-CF4 mixtures and the R&D for fiducializing DRIFT and retrofitting the present DRIFT detector with such a system. The Broader impacts of this work include the training of undergraduates in increasingly rare small-scale experiments, giving them exposure to a wide range of hardware and software experience. Finally, the DRIFT detector technology has promising applications to axion searches, Homeland Security and double-beta decay experiments.