Processing an Additional Quantity of Ge-76 for the Majorana Demonstrator

为马约拉纳演示机加工额外数量的 Ge-76

• 批准号: 1206314
• 负责人: Frank Avignone
• 金额: $ 29.88万
• 依托单位: University South Carolina Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-15 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1206314&HistoricalAwards=false
• 关键词: Processing; Additional; Quantity; Ge; 76

A comprehensive program in neutrino-less double-beta decay is very timely. A principal finding of the APS Multidivisional Study stated: "We recommend, as a high priority, a phased program of sensitive searches for neutrino-less nuclear double-beta decay." The intellectual merit of this award is based on the fact that the observation of such a decay is the only practical way to determine if neutrinos are Majorana particles (their own antiparticles). This exotic decay is the most sensitive test of lepton number conservation, an important symmetry in elementary-particle physics. In fact, if neutrinos are Majorana particles, a measurement of the decay half-life would yield the effective Majorana mass of the electron neutrino. This result, combined with neutrino oscillation data, would determine all three neutrino-mass eigenvalues. Is leptogenesis even a possibility? Yes, but only if neutrinos are Majorana particles. These funds are awarded to assist the Majorana Demonstrator (MJD) experiment searching for neutrino-less double beta decay in germanium -76 (Ge-76). The specific and limited work is to carry-out the highly technical conversion of germanium oxide (GeO2) into metallic form suitable for the fabrication of Ge detector units. The PI leads the Task in the MJD R&D Project responsible for the procurement of enriched GeO2, its reduction to metal, zone refinement to detector quality Ge metal, and reprocessing of the scrap material. The PIs formed the team that equipped the facility and acquired the necessary equipment for the Ge processing and reprocessing; they are now operating the facility. Recently two Russian Institutes have agreed to loan MJD between 8.7 and 14.5-kg of enriched GeO2. The cost of processing this material was not covered in the original proposal. Accordingly, this funding is provided for the reduction, zone refinement and reprocessing of this material, and for new R&D to develop more efficient scrap reprocessing. This new loaned GeO2 will significantly extend the science reach of the MJD.Broader impacts: One broader impact would be an important contribution to cosmology. Another is, and has been, new detector technology for National and Homeland security. A third broader impact is new ultra-low background Ge-detector technology for other basic and applied sciences. In fact, this technology has broad application in environmental radiological surveys.

一个全面的计划，在中微子少双β衰变是非常及时的。美国物理学会多部门研究的一项主要发现指出：“我们建议，作为一个高度优先事项，对中微子较少的核双β衰变进行分阶段的灵敏搜索。“这个奖项的学术价值是基于这样一个事实，即对这种衰变的观察是确定中微子是否是马约拉纳粒子（它们自己的反粒子）的唯一实用方法。这种奇特的衰变是轻子数守恒最敏感的检验，轻子数守恒是基本粒子物理学中一个重要的对称性。事实上，如果中微子是马约拉纳粒子，测量衰变半衰期将得到电子中微子的有效马约拉纳质量。这个结果，结合中微子振荡数据，将确定所有三个中微子质量本征值。纤体创生有可能吗？是的，但前提是中微子是马约拉纳粒子。这些资金用于协助马约拉纳演示器（Majorana Demonstrator，MJD）实验寻找锗-76（Ge-76）中的无中微子双β衰变。具体的和有限的工作是进行高技术转换的氧化锗（GeO 2）到金属的形式适合锗探测器单元的制造。PI领导MJD研发项目中的任务，负责采购浓缩的GeO 2，将其还原为金属，将区域精炼为探测器质量的Ge金属，以及废料的再处理。PI组成了装备该设施的团队，并获得了锗加工和后处理所需的设备;他们现在正在运营该设施。最近，两个俄罗斯研究所已同意借给MJD 8.7至14.5公斤的浓缩二氧化锗。原提案中没有包括处理这些材料的费用。因此，该资金用于该材料的还原、区域细化和后处理，并用于新的研发，以开发更有效的废料后处理。这一新借出的GeO 2将大大扩展MJD的科学范围。更广泛的影响：一个更广泛的影响将是对宇宙学的重要贡献。另一个是，而且一直是，国家和国土安全的新探测器技术。第三个更广泛的影响是用于其他基础和应用科学的新的超低本底锗探测器技术。实际上，该技术在环境放射性调查中有着广泛的应用。