ASTREA: Accelerator mass spectrometry Survey of Trace Radionuclides for Experiments in Astroparticle physics

ASTREA：用于天体粒子物理学实验的痕量放射性核素的加速器质谱调查

• 批准号: SAPPJ-2021-00033
• 负责人: Kieser, William
• 金额: $ 7.5万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Project
• 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=762631
• 关键词: ASTREA; Accelerator; mass; spectrometry; Survey

In the last three decades, tremendous advances in experimental particle physics have enabled strong progression in the search for neutrinoless double beta decay (0?ßß) and the direct detection of dark matter (DM). Tabletop instruments have become multi-tonne underground detectors with excellent sensitivity to extremely rare interactions. Critical to this progress has been the reduction of residual natural radioactive backgrounds in the detectors by many orders of magnitude, accomplished mainly through material screening, before and during detector construction. Every material and component for building such giants has to be thoroughly analyzed and, if possible, optimized, as the slightest natural radioactive contamination can ruin the experiment's sensitivity by overwhelming the expected signal. Many technical advances, as well as underground installation have contributed to the success of past and current experiments. But we have reached material screening requirements that often cannot be met by typical methods. Accelerator Mass Spectrometry (AMS), an established technique in other fields, provides a beacon of hope to achieve the ultimate sensitivity. AMS uses a particle accelerator to enhance sensitivity and offer unique and outstanding advantages: - direct scanning of electrically conducting materials; this compares favourably with the only other direct method, gamma spectroscopy using a Ge detector, - total molecular background suppression, an advantage over regular high sensitivity mass spectrometry techniques like ICP-MS. - single ion sensitivity using gas ionization detectors and high resolution alternating magnetic and electric sectors, that enable noise-free detection and a series of signal to background optimization strategies. - application to screening for medium/short lifetime isotopes, e.g. 210Pb in a wide array of plastics and other insulators used for in-situ electronics and high voltage systems, In this request, we consider AMS material screening contributions targeted to three specific projects that have significant Canadian contributions and leadership: nEXO, NEWS-G and DEAP/DarkSide, and which are considering operating at SNOLab , one of the deepest and cleanest underground laboratories in the world. We propose to investigate the trace radioactivity due to U and Th chains, measure the concentration of 210Pb and 226Ra, in copper, titanium, acrylic and thin polymer films. The A. E. Lalonde AMS (AEL-AMS) facility at the University of Ottawa, the only AMS laboratory in Canada, operates a 3 MV, multi-element AMS system, specifically designed to sensitively and efficiently measure elements as massive as the actinides. AEL-AMS has implemented sample preparation chemistry labs equipped to handle a wide array of analyte atoms and sample matrices and has a mandate to develop new applications and the required protocols and technical infrastructure to facilitate such analyses.

在过去的三十年中，实验粒子物理学的巨大进步在寻找神经素的双β衰减（0？ßß）和直接检测暗物质（DM）方面已经实现了强烈的进步。桌面仪器已成为多吨的地下探测器，对极为罕见的相互作用具有出色的敏感性。这一进展至关重要的是，探测器中残留的自然放射背景的降低了许多数量级，主要是通过材料筛选，在检测器构造之前和期间完成的。建造此类巨头的每种材料和组件都必须进行彻底分析，并在可能的情况下进行优化，因为略有天然的放射性污染可能会通过压倒预期信号来破坏实验的灵敏度。许多技术进步以及地下装置都为过去和当前实验的成功做出了贡献。但是我们达到了材料筛选要求，通常无法通过典型的方法来满足。加速器质谱法（AMS）是在其他领域的建立技术，它提供了希望达到最终敏感性的希望的灯塔。 AMS使用粒子加速器来增强灵敏度并具有独特而出色的优势： - 直接扫描电动导电材料；这与使用GE检测器的唯一其他直接方法，γ光谱法相比， - 总分子背景抑制，优于常规高灵敏度质谱技术（如ICP -MS）。 - 使用气体电离检测器和高分辨率替代磁性和电扇区的单个离子灵敏度，可实现无噪声检测以及一系列信号到背景优化策略。 - 应用中等/短寿命同位素的筛查，例如210Pb in a wide array of plastics and other insulators used for in-situ electronics and high voltage systems, In this request, we consider AMS material screening contributions targeted to three specific projects that have significant Canadian contributions and leadership: nEXO, NEWS-G and DEAP/DarkSide, and which are considering operating at SNOLab , one of the deepest and cleanest underground laboratories in the world.我们建议在铜，钛，丙烯酸和薄聚合物膜中研究由于U和TH链引起的痕量放射性，测量210pb和226ra的浓度。渥太华大学的A. E. Lalonde AMS（AEL-AMS）设施是加拿大唯一的AMS实验室，经营3 mV的多元素AMS系统，专门设计用于敏感有效地测量像肌动剂一样大的元素。 AEL-AMS已经实施了配备了各种分析物原子和样品材料的样本制备化学实验室，并具有开发新应用程序以及所需的方案和技术基础架构的任务，以促进此类分析。