RII Track-4: Operating High Purity Germanium Detectors in Liquid Scintillator

RII Track-4：在液体闪烁体中操作高纯度锗探测器

• 批准号: 1929097
• 负责人: Wenqin Xu
• 金额: $ 20.75万
• 依托单位: University of South Dakota Main Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1929097&HistoricalAwards=false
• 关键词: RII; Track; Operating; Purity; Germanium

Neutrinos are subatomic particles abundantly produced in Nature. It has been challenging to investigate the intrinsic properties of the ghostly neutrinos, because they can pass through instruments and materials with barely any interactions. Thanks to advancements of technology as well as long-term commitment of the science community, recent breakthroughs have revealed critical yet unexpected properties of neutrinos, such as the fact that neutrinos have non-zero masses. New knowledge on neutrinos can probe fundamental symmetries in Nature and could shed light on the key mystery of matter-over-antimatter excess in the universe. Extrasolar neutrinos are also one of the messengers carrying information about the universe that can lead us to a more complete picture of the universe. This proposal aims at developing techniques that could facilitate experiments to deepen our understanding of neutrinos, including probing the origin of non-zero neutrino masses. It will also advance the collaboration between the University of South Dakota (USD) and Los Alamos National Laboratory (LANL) in new directions. The transformative new expertise gained by the USD group will enhance the group's research capability in Underground Science and Engineering, one of the high value research areas and assets aligned with target industry sectors for South Dakota.The PI at USD plans to visit LANL to develop active veto techniques employing liquid argon (LAr), intended for the proposed Large Enriched Germanium Experiment for Neutrinoless double-beta Decay (LEGEND) project. Both the home and host groups are LEGEND collaborators. The LEGEND collaboration aims to develop a phased, Ge-76 based neutrinoless double-beta decay (NLDBD) experimental program with discovery potential at a half-life beyond 10e28 years. LEGEND will operate up to one tonne of high-purity germanium detectors inside a large volume of LAr. The LAr shield serves as an active veto that is powerful in eliminating a wide range of backgrounds for NLDBD. Specifically, the PI and trainees will collaborate with LANL researchers to convert an existing cryostat at LANL into a LAr test stand with purification capability and light collection instrumentation. We will directly immerse and operate high-purity germanium detectors inside liquid argon. Through this collaborative research between USD and LANL, we can evaluate the overall performance of the integrated system and improve our understanding of the background rejection performance of a LAr active veto. In addition to advancing the preparation for the LEGEND project, this Research Fellowship will arm the PI with expertise on liquid scintillator technologies and enable the PI to sustain his career in experimental neutrino physics in the long-term. A combination of hardware infrastructure and technical expertise at LANL is essential to carry out the proposed activities.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.

中微子是自然界中大量产生的亚原子颗粒。研究幽灵中微子的内在特性是一项挑战，因为它们几乎没有任何相互作用的仪器和材料。得益于技术的进步以及科学界的长期承诺，最近的突破揭示了中微子的关键但出乎意料的特性，例如中微子具有非零群众的事实。关于中微子的新知识可以探讨自然界中的基本对称性，并可以阐明宇宙中物质过剩的关键奥秘。外中微子也是携带有关宇宙信息的使者之一，可以使我们对宇宙进行更完整的了解。该建议旨在开发可以促进实验以加深我们对中微子的理解的技术，包括探测非零中微子肿块的起源。它还将在新的方向上推进南达科他大学（USD）和洛斯阿拉莫斯国家实验室（LANL）之间的合作。 The transformative new expertise gained by the USD group will enhance the group's research capability in Underground Science and Engineering, one of the high value research areas and assets aligned with target industry sectors for South Dakota.The PI at USD plans to visit LANL to develop active veto techniques employing liquid argon (LAr), intended for the proposed Large Enriched Germanium Experiment for Neutrinoless double-beta Decay (LEGEND) project.家庭和主机团体都是传奇的合作者。传奇合作旨在开发基于GE-76的基于GE-76的中微子双β衰减（NLDBD）实验计划，其发现潜力超过10E28年的半衰期。传奇人物将在大量LAR内运行多达一吨高纯锗探测器。 LAR Shield是一种活跃的否决权，在消除NLDBD的各种背景方面具有强大的功能。具体来说，PI和受训者将与LANL研究人员合作，将LANL现有的低温恒温器转换为具有纯化能力和轻型收集仪器的LAR测试架。我们将直接浸入并在液体氩气中操作高纯晶式探测器。通过USD和LANL之间的这项合作研究，我们可以评估集成系统的整体性能，并提高对LAR主动否决的背景拒绝绩效的理解。除了推进传奇项目的准备外，这项研究奖学金还将以液体闪烁技术的专业知识为PI武装，并使PI长期以来能够维持其在实验性中微子物理学领域的职业。 LANL硬件基础架构和技术专业知识的结合对于开展拟议的活动至关重要。该奖项反映了NSF的法定任务，并且使用基金会的知识分子优点和更广泛的影响审查标准，被认为值得通过评估来获得支持。