DUSEL R&D: Benchmarking Hadronic Showers Underground: Correlating Cosmogenic Neutron Production with High Multiplicity Shower Events

寻找暗物质粒子的实验是深层地下科学的关键科学驱动力之一。然而，地下实验室中快中子的核反冲是可能的暗物质探测最具挑战性的背景之一，而且这种背景的速率很难量化。暗物质实验依靠数值蒙特卡罗模拟来预测这些中子的背景速率，然而由于缺乏适当的数据进行直接比较，这些过程的模拟是不确定的。该合同将使PI能够通过与Case/UCSB基准宇宙生成中子背景多重度计的合作，测量高能宇宙射线产生的中子含量和多重度。通过将Case/UCSB加载gd的闪烁体探测器定位在μ子屏蔽下，该小组可以将μ子系统大面积覆盖的强子雨采样与多重度计提供的更小但更详细的中子敏感信息交叉关联。中子多重性的数据将允许测量潜在的中子产生过程，也提供有关母体高能中子谱的信息。总之，速率、多样性和能量测量将有助于使模拟代码规范化，并提供对底层过程建模缺陷的洞察。这项工作的广泛影响延伸到许多其他地下实验，这些实验依赖于了解中子背景环境。能够以更高的可靠性预测这一背景将很好地服务于社区，并为旨在在未来DUSEL的更深地点操作的实验提供改进的推断。用于μ子屏蔽的技术为新一代物理学家提供了一个实践的、短期项目的培训基地。

Experiments which search for dark matter particles are one of the critical science drivers for deep underground science. However, nuclear recoils from fast neutrons in underground laboratories are one of the most challenging backgrounds to possible dark matter detection and the rate of this background is poorly quantified. Dark matter experiments rely on numerical Monte Carlo simulations to predict the background rate due to these neutrons, yet the simulation of these processes is uncertain because of the lack of appropriate data for direct comparison.This award will enable the PI to measure the neutron content and multiplicity of the showers produced by high energy cosmic rays by joining forces with the Case/UCSB Multiplicity Meter for Benchmarking Cosmogenic Neutron Backgrounds. By locating the Case/UCSB Gd-loaded scintillator detector under the muon shield, this group can cross-correlate hadronic showers sampled by the large area coverage of the muon system with the smaller, but more detailed, neutron-sensitive information from the Multiplicity Meter. The data on neutron multiplicity would allow the underlying neutron production processes to be measured, also providing information about the parent high-energy neutron spectrum. Together, the rate, multiplicity and energy measurements will help to normalize the simulation codes and provide insight into deficiencies in modeling the underlying processes. The broader impacts of this work extend to the many other underground experiments that rely on knowing the neutron background environment. Being able to predict this background with greater reliability will serve the community well, and provide improved extrapolations for experiments aiming to operate in deeper sites at a future DUSEL. The technology used for the muon shield provides a training ground for a new generation of physicists with hands-on, short term projects.