Probing Solar Axions with X-ray Optics for BabyIAXO

暗物质的性质是21世纪物理学的一个重要问题。轴子是暗物质最有动力的候选者之一，因为它们可以解决我们理解基本粒子相互作用的潜在问题，而其他类似轴子的粒子是许多新物理理论的一般预测，特别是弦理论。轴子将改变在恒星内部极端环境中发生的过程，例如在我们的太阳内部。国际轴子天文台(IAXO)将搜索来自太阳的轴子，开启了对广泛质量范围内的轴子和轴子类粒子的新的敏感性。这项提议的目标是建造一个聚焦X射线望远镜，并在分析方面领先于探索IAXO的BabyIAXO。这项工作还将根据美国物理研究所和美国国家科学院的建议，扩大教师在本科课程中促进“归属感”的方法培训，并为本科生和研究生提供实际操作的仪器专业知识，促进这项X射线望远镜技术的更广泛应用。IAXO仪器是下一代轴子日光仪，旨在通过实验室的强磁场搜索从太阳返回到X射线光子的轴子。BabyIAXO将为所有相关规模的IAXO子系统推进技术，同时还提供新的物理覆盖范围和发现潜力。BabyIAXO和IAXO是仅有的两个超越研发阶段的实验，它们对MEV到EV质量范围内的QCD轴子很敏感，这是由许多暗物质场景以及可能构成所有暗物质的大范围阿尔卑斯山驱动的。这项提议的目标是为BabyIAXO建造核心X射线光学系统；将光学响应引入模拟和分析链；并为BabyIAXO数据的试运行和初步分析做出贡献。具有成本效益的大面积X射线光学元件是减小探测器尺寸和本底的关键，同时仍可利用较大的磁铁区域，从而实现轴子日光镜灵敏度的飞跃。这项工作将利用建造NuSTAR X射线光学系统的专业知识和设施，BabyIAXO和IAXO光学系统就是基于该系统建造的。因此，在学生培训和材料方面的适度投资，就可以让美国成为IAXO X射线光学系统和下一代太阳轴子研究的领先者。这项工作的更广泛影响包括(I)培养新一代乐器演奏家，帮助确保美国建立一支具有全球竞争力的STEM劳动力队伍，(Ii)扩大与教育研究人员在培养本科生STEM课堂“归属感”的方法上的现有合作，帮助确保这支队伍更好地反映国家的多样性，以及(Iii)这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The nature of dark matter is a driving question of 21st century physics. Axions are among the best motivated candidates for dark matter, as they could solve underlying problems in our understanding of fundamental particle interactions, and other axion-like particles are a generic prediction of many new physics theories, in particular string theory. Axions would alter the processes taking place within the extreme environments of stellar interiors, such as within our own Sun. The International Axion Observatory (IAXO) will search for axions from our Sun, opening novel sensitivity to axions and axion-like particles across a broad range of masses. The goal of this proposal is to construct a focusing X-ray telescope and take leadership in analysis for BabyIAXO, the pathfinder to IAXO. This work will also expand instructor training in methods to promote “belonging” in undergraduate courses, in line with recommendations from the American Institute of Physics and the National Academies, as well as provide undergraduate and graduate students with hands-on expertise in instrumentation, facilitating broader applications of this X-ray telescope technology.The IAXO instrument is a next-generation axion helioscope, designed to search for axions from the Sun that are reconverted into X-ray photons via a strong laboratory magnetic field. BabyIAXO will advance technology for all IAXO subsystems at relevant scale while also offering novel physics reach and discovery potential. BabyIAXO and IAXO are the only experiments beyond the R&D phase sensitive to QCD axions in the meV to eV mass range, which is motivated by many dark matter scenarios, as well as a broad range of ALPs that could constitute all of dark matter. The goals of this proposal are to construct the inner core X-ray optic for BabyIAXO; lead implementation of the optics response into the simulation and analysis chain; and contribute to commissioning and initial analysis of BabyIAXO data. Cost-effective, large-area X-ray optics are key to reducing detector size and background while still exploiting large magnet areas, allowing a leap forward in axion helioscope sensitivity. This work will leverage the expertise and facilities from construction of the NuSTAR X-ray optics, on which the BabyIAXO and IAXO optics are based. Thus, a modest investment in student training and materials can establish the US as a leader of the IAXO X-ray optics system and the next generation of solar axion searches. The broader impacts of this work include (i.) educating a new generation of instrumentalists, helping ensure the US builds a globally competitive STEM workforce, (ii.) expanding the PI’s established collaborations with educational researchers on methods that foster “belonging” in undergraduate STEM classrooms, helping ensure that this workforce better reflects the diversity of the nation, and (iii.) enabling broader applications of segmented glass X-ray optics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.