DUSEL R&D: BetaCage: A Screener of Ultra-Low-Level Radioactive Surface Contamination

杜塞尔R

• 批准号: 0703838
• 负责人: Richard Schnee
• 金额: $ 20.08万
• 依托单位: Case Western Reserve University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-06-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0703838&HistoricalAwards=false
• 关键词: DUSEL; R& BetaCage; Screener; Ultra

One of the great promises of the proposed Deep Underground Science and Engineering Laboratory (DUSEL) is to provide space shielded from cosmic-ray background particles for experiments that require extremely low backgrounds. These experiments seek to study the fundamental laws of physics, such as our understanding of how the sun shines, whether the neutrino is its own antiparticle, and what is the dark matter pervading the universe. However, to take full advantage of the shielding from cosmic rays, these experiments must be built from components with such low levels of radioactivity that even the best screening facilities available in shielded sites at the Earth's surface are insufficiently sensitive. New screening facilities must be built underground to allow these low-background experiments to succeed. This proposal seeks resources to build a detector that would be the world's most sensitive screener of radioactive surface contamination such as low-energy-electron emitting radioisotopes. This detector, dubbed the "BetaCage," will consist of an ultra-low-background multi-wire proportional chamber using neon gas at atmospheric pressure. This screener would have applications for rare-interaction physics experiments and trace radioactive counting applications. The BetaCage would detect electron rates low enough for the 150 kg stage of SuperCDMS to reach its design sensitivity for WIMP dark matter without being limited by misidentified low-energy electrons. The BetaCage would also be ideal for screening alphas, with important applications for dark matter searches, solar neutrino experiments, and neutrinoless double beta decay experiments, as well as for the Si-chip industry and for other scientific fields, many of general societal interest. Additional broader impacts will include the training of scientists in radiation-detection technologies and low-background techniques.

拟议的深层地下科学与工程实验室（DUSEL）的伟大承诺之一是为需要极低背景的实验提供免受宇宙射线背景粒子影响的空间。这些实验旨在研究物理的基本定律，例如我们对太阳如何发光、中微子是否是其自身反粒子以及弥漫在宇宙中的暗物质是什么的理解。然而，为了充分利用宇宙射线的屏蔽，这些实验必须使用放射性水平极低的组件来建造，以至于即使是地球表面屏蔽地点可用的最好的屏蔽设施也不够灵敏。必须在地下建造新的筛选设施才能使这些低本底实验取得成功。 该提案寻求资源来建造一种探测器，该探测器将成为世界上最灵敏的放射性表面污染（例如低能电子发射放射性同位素）筛查器。该探测器被称为“BetaCage”，由一个在大气压下使用氖气的超低背景多线比例室组成。该筛选器可用于稀有相互作用物理实验和痕量放射性计数应用。 BetaCage 将检测到足够低的电子速率，使 SuperCDMS 的 150 kg 级能够达到其对 WIMP 暗物质的设计灵敏度，而不会受到错误识别的低能电子的限制。 BetaCage 也非常适合筛选 α 粒子，在暗物质搜索、太阳中微子实验和无中微子双 β 衰变实验以及硅芯片工业和其他科学领域（许多引起社会普遍兴趣）方面具有重要应用。其他更广泛的影响将包括对科学家进行辐射探测技术和低本底技术的培训。