CAREER: Development of a New Generation of Gas-based Detectors for the Directionality Signature from Dark Matter

在这个精确宇宙学的时代，测量表明，普通物质（质子和中子）只占宇宙总物质密度的15%。其余的部分，其作用我们只能从引力上看到，似乎是黑暗的。探测和识别暗物质被广泛认为是21世纪宇宙学中最重要的问题之一。目前的粒子物理模型表明，暗物质可能是大爆炸遗留下来的弱相互作用大质量粒子（wimp）。直接探测wimp的努力受到相互作用概率小和模拟预期暗物质信号的大背景的阻碍。幸运的是，存在一些独特的暗物质特征，如果加以利用，可以用来区分背景。这些都是基于太阳-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实验室框架中核反冲方向的昼夜调制。在目前的暗物质实验搜索中，只有一种，即轨道定向反冲识别（DRIFT），配备了检测这种方向性特征的设备。本课题的主要目的是为未来的定向敏感暗物质探测器实验研究新型探测器。这些研究将集中于提高DRIFT测量方向性的灵敏度，通过充分利用halo wimp的方向特征，同时保持DRIFT良好的背景抑制能力、内在的低可维护性和单位质量的低成本。本研究的目标是通过在实验室中测量新技术的性能来量化新技术的优缺点，并评估在未来大质量定向暗物质实验中使用这些新技术的可行性。这项工作的更广泛影响包括对本科生和研究生（包括代表性不足的少数民族）的培训。此外，还将为初高中教师的专业发展制定有针对性的外展计划。作为该计划的一部分，每年将为新墨西哥州的教师提供为期一天的研讨会，随后是为期两周的强化课程，研究生学分可获得教育学硕士学位。这将在北极星天文中心和西南科学教育研究所的合作和支持下进行。

In this era of precision cosmology, measurements suggest that ordinary matter (protons and neutrons) makes up a mere 15% of the total matter density in the Universe. The rest, whose effect we can only see gravitationally, appears to be dark. The goal of detecting and identifying dark matter is widely recognized as one of the most important problems in 21st century cosmology. Current particle physics models suggest that dark matter might be 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 which mimic expected dark matter signals. Fortunately, a number of unique dark matter signatures exist which, if exploited, can be used to discriminate against backgrounds. These are based on the predicted behavior of the WIMP flux as the Sun-Earth system moves through the galaxy. The largest and most robust of these signatures is a day-night modulation of nuclear recoil directions in the lab frame. Of current experimental searches for dark matter only one, Directional Recoil Identification From Tracks (DRIFT), is equipped to detect this directionality signature. The main subject of this proposal is to experimentally study novel detectors for future directionally sensitive dark matter detectors. These studies will focus on improving DRIFT's sensitivity for measuring directionality by taking full advantage of the directional signature from halo WIMPs while maintaining DRIFT's good background rejection capabilities, intrinsic low-maintainability, and low cost per unit mass. The goals of this research are to quantify the advantages and disadvantages of the new technologies by measuring their performance in the laboratory, and to assess the feasibility of employing these new technologies in future, large mass directional dark matter experiments.Broader impacts of this work include the training of undergraduate and graduate students (including underrepresented minorities). Additionally, a targeted Outreach Program for the professional development of middle- and high-school teachers will be developed. As part of this program, each year a 1-day workshop will be offered, followed by a 2-week intensive course, with graduate credit towards a M.A. in Education, for teachers across New Mexico. This will take place in collaboration with and support from the Lodestar Astronomy Center and the Science Education Institute of the Southwest.