Collaborative research for Underground Science: Barium Tagging Techniques for EXO

地下科学合作研究：EXO 的钡标记技术

• 批准号: 1132382
• 负责人: Giorgio Gratta
• 金额: $ 73.38万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-15 至 2016-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1132382&HistoricalAwards=false
• 关键词: Collaborative; research; Underground; Science; Barium

The observation of neutrinoless double beta decay will help determine the masses of neutrinos, discover lepton number violation and reveal if two-component Majorana fermions exist in Nature. EXO, a multi-tonne neutrinoless double beta decay experiment employing xenon enriched to ~80% in the isotope Xenon-136, is now taking data at the WIPP underground site in New Mexico. However, the next generation of such experiments requires advanced background reduction methods to reach Majorana neutrino mass sensitivities below 0.01 eV.EXO is developing a novel technique to tag the Barium (Ba) produced in the final state of the neutrinoless double beta decay using atomic spectroscopy. This technique has the promise of drastically reducing radioactive backgrounds, providing a clean and un-ambiguous measurement with unprecedented sensitivity. Recent breakthroughs have been obtained in the Ba-tagging front. These groups have produced, for the first time, Ba transport and tagging efficiencies above 1%. The R&D work funded with this award builds on such breakthroughs and aspires to provide the first demonstration of high efficiency tagging of individual Ba atoms in liquid xenon. Broader impacts: While the primary scientific goal of this proposal is in the field of neutrino physics, its broader impact is substantial. The techniques being developed span a range of topics, from nuclear and particle astrophysics, to AMO, surface physics and material science. This research, if successful, is likely to be applicable to other problems in science and technology, where the high efficiency transfer and identification of single atoms would be of interest. Examples include trace analysis for homeland security applications and the detection of rare phenomena. The team is also planning to continue the summer program integrating high school teachers into their labs.

中微子双β衰变的观察将有助于确定中微子的质量，发现Lepton数量违规，并揭示自然界中是否存在两个组成部分的Majorafana fermions。 Exo是一种多吨中心元双β衰减实验，采用Xenon富集至同位素Xenon-136的80％，现在正在新墨西哥州的Wipp Underground网站上获取数据。但是，下一代这样的实验需要高级背景减少方法，以达到低于0.01 ev的主要中微子质量敏感性。EXO正在开发一种新型技术，以使用原子光谱法对中上午双β衰减的最终状态标记钡（BA）。该技术具有大幅度降低放射性背景的希望，提供了具有前所未有的灵敏度的干净且毫不含糊的测量。 在BA标记的阵线中已经获得了最近的突破。这些群体首次产生了超过1％以上的BA运输和标记效率。由该奖项资助的研发工作以此类突破为基础，并渴望首次展示液体Xenon中单个BA原子的高效标记。更广泛的影响：尽管该提案的主要科学目标是中微子物理学领域，但其更广泛的影响是巨大的。从核和粒子天体物理学到AMO，表面物理学和材料科学，开发的技术涵盖了一系列主题。如果成功的话，这项研究可能适用于科学技术的其他问题，在这些问题中，单个原子的高效率转移和识别将引起人们的兴趣。例子包括用于国土安全应用的痕量分析和检测稀有现象。该团队还计划继续夏季计划，将高中教师纳入实验室。