Optical characterization of materials at low temperatures for rare-event searches

用于稀有事件搜索的材料在低温下的光学表征

• 批准号: SAPIN-2019-00044
• 负责人: DiStefano, Philippe
• 金额: $ 2.77万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=763242
• 关键词: Optical; characterization; materials; low; temperatures

What constitutes the bulk of the matter in the universe, and why there is an asymmetry between matter and anti-matter, constitute two important open questions in physics and astronomy. Particle physics explores answers by looking for rare events, including the interactions of exotic new dark-matter particles from beyond the standard model, and unusual decays involving neutrinos. I have a longstanding interest in these searches, and in developing new detectors for them. Over the next five years, my group and I will measure the optical properties of materials at temperatures down to a few degrees above absolute 0 to build improved detectors for rare-event searches. For instance, Li2MoO4 and ZnSe are compounds that may provide evidence of elusive neutrinoless double beta decay. NaI scintillators doped with radioactive elements will provide a better understanding of how these detectors respond to particles of different types that may be a background for dark matter. We will investigate wavelength shifters at various temperatures in order to enhance the capacities of future noble liquid detectors. We will study how mechanical stress affects the light yield of CsI scintillator. Moreover, we will test new light detectors, SiPMs, and their electronics, down to 4 K, to detect low-temperature scintillation, caused for instance by dark matter particles in noble liquids or other scintillators. Lastly, in the first year of this project, we will wrap-up KDK, an experiment to measure a rare decay of potassium, a naturally-occurring element, which is a radioactive background in many rare-event searches. Potassium may play a role in understanding the controversial claim of dark matter discovery by the DAMA collaboration. This work will support the strong rare-event search program at SNOLAB in Canada, and increase the chance that the next generation, 300-ton scale, noble liquid experiments are located there. Over its 5-year course, this program will support and train five undergraduate and four graduate students, and contribute to the training of a fifth graduate student and of a postdoctoral researcher, whose salaries are both paid by the McDonald Institute.

宇宙中物质的主体是什么，以及为什么物质和反物质之间存在不对称性，构成了物理学和天文学中两个重要的悬而未决的问题。粒子物理学通过寻找罕见事件来探索答案，包括标准模型之外的奇异新暗物质粒子的相互作用，以及涉及中微子的不寻常衰变。我对这些搜索有着长期的兴趣，并为它们开发新的探测器。在接下来的五年里，我和我的团队将在绝对零度以上几度的温度下测量材料的光学特性，以建立用于稀有事件搜索的改进型探测器。例如，Li2MoO4和ZnSe是可能提供难以捉摸的无中微子双β衰变证据的化合物。掺杂放射性元素的碘化钠探测器将更好地了解这些探测器如何对可能是暗物质背景的不同类型的粒子作出反应。我们将研究在不同温度下的波长移位器，以提高未来的惰性液体探测器的能力。我们将研究机械应力如何影响碘化铯闪烁体的光产额。此外，我们将测试新的光探测器SiPM及其电子器件，低至4 K，以探测低温闪烁，例如由惰性液体或其他闪烁器中的暗物质粒子引起的闪烁。最后，在这个项目的第一年，我们将总结KDK，这是一个测量钾的罕见衰变的实验，钾是一种天然存在的元素，在许多稀有事件搜索中是放射性背景。钾可能在理解DAMA合作发现暗物质的争议性声明中发挥作用。 这项工作将支持加拿大SNOLAB的强稀有事件搜索计划，并增加下一代300吨级惰性液体实验的机会。在其5年的课程，该计划将支持和培训五名本科生和四名研究生，并有助于第五名研究生和博士后研究员的培训，他们的工资都由麦当劳研究所支付。