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

在这个精确宇宙学的时代，测量表明，普通物质只占宇宙总物质密度的一小部分。其余的部分，其作用我们只能从引力上看到，似乎是黑暗的。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。直接探测wimp的努力受到小相互作用概率和模拟预期暗物质信号的大背景的阻碍。幸运的是，存在许多独特的暗物质特征，可以用来区分背景，并果断地识别WIMP相互作用。根据太阳-地球系统在星系中移动时WIMP通量的预测行为，这些特征中最大和最强大的是在实验室框架中昼夜调制的核反冲方向。这一建议的智力价值在于轨道定向后坐力识别（DRIFT）实验独特而强大的能力被用于解决当今科学中最重要的问题之一。该合同将为该小组提供资金支持，并为CS2-CF4混合物提供一种新的气体系统，以及对DRIFT进行验证和改造现有DRIFT探测器的研发经费。这项工作的更广泛的影响包括在越来越罕见的小规模实验中训练本科生，使他们接触到广泛的硬件和软件经验。最后，DRIFT探测器技术在轴子搜索、国土安全以及双β衰变实验等方面有着广阔的应用前景。

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.