The Search for Double Beta Decay With Germanium Detectors: Past, Present, and Future
The Search for Double Beta Decay With Germanium Detectors: Past, Present, and Future
复制标题
用锗探测器寻找双贝塔衰变：过去、现在和未来
DOI：
10.3389/fphy.2019.00006
复制
发表时间：
2019
影响因子：
3.1
通讯作者：
S. Elliott
中科院分区：
文献类型：
--
作者：
F. T. Avignone III;S. Elliott
高纯锗探测器具有优异的能量分辨率；双贝塔衰变中使用的最好的技术。由于无中微子双β衰变取决于在背景连续体上寻找罕见峰值，因此这种优势使该技术能够始终如一地提供领先的结果。这些实验的核心是Ge晶体，其纯度非常高。它们没有可测量的 U 或 Th 污染。减少与电子、低温冷却和屏蔽相关的背景的额外努力非常成功，从而延长了生产力。 Fiorini米兰小组于1967年发表的第一个实验建立了基准半衰期极限$>3\times10^{20}$年。随着 USC-PNNL、UCSB 和 Milan 小组的早期工作，这一界限得到了改善，每年的限额超过 10^{23}$。海德堡-莫斯科和南加州大学-太平洋西北国家实验室的合作率先使用富集Ge来制造探测器。两个小组还启动了分析脉冲波形的技术，以抑制 $\gamma$ 射线背景。这些步骤将限额扩大到每年 10^{25}$ 多一点。 2000 年，海德堡-莫斯科合作的一个子集声称观测到了双贝塔衰变。最近，\MJ\ 和 GERDA 合作开发了新的检测器技术，可优化脉冲波形分析。因此，GERDA 合作通过将探测器直接浸入无线电纯液氩中，采用革命性的屏蔽方法驳斥了观测的说法。 2018 年，\MJ\ 合作使用经典的真空低温恒温器和高 Z 屏蔽，通过开发在探测器附近使用的非常纯的材料，达到了接近 GERDA 的背景水平。 GERDA 和 \MJ\ 共同提供了接近每年 10^{26}$ 美元的限额。在本文中，我们详细介绍了 Ge 探测器在双 β 衰变中的历史应用，并解决了其优点和缺点。我们还总结了许多 \MJ\ 和 GERDA 合作者与其他科学家共同努力催生 LEGEND 合作的现状和未来。 LEGEND 将利用这两个实验的最佳特性，通过吨级实验将半衰期限制延长到每年 10^{28}$ 以上。
High Purity Germanium Detectors have excellent energy resolution; the best among the technologies used in double beta decay. Since neutrino-less double beta decay hinges on the search for a rare peak upon a background continuum, this strength has enabled the technology to consistently provide leading results. The Ge crystals at the heart of these experiments are very pure; they have no measurable U or Th contamination. The added efforts to reduce the background associated with electronics, cryogenic cooling, and shielding have been very successful, leading to the longevity of productivity. The first experiment published in 1967 by the Milan group of Fiorini, established the benchmark half-life limit $>3\times10^{20}$ yr. This bound was improved with the early work of the USC-PNNL, UCSB and Milan groups yielding limits above $10^{23}$ yr. The Heidelberg-Moscow and USC-PNNL collaborations pioneered the use of enriched Ge for detector fabrication. Both groups also initiated techniques of analyzing pulse waveforms to reject $\gamma$-ray background. These steps extended the limits to just over $10^{25}$ yr. In 2000, a subset of the Heidelberg-Moscow collaboration claimed the observation of double beta decay. More recently, the \MJ\ and GERDA collaborations have developed new detector technologies that optimize the pulse waveform analysis. As a result, the GERDA collaboration refuted the claim of observation with a revolutionary approach to shielding by immersing the detectors directly in radio-pure liquid argon. In 2018, the \MJ\ collaboration, using a classic vacuum cryostat and high-Z shielding, achieved a background level near that of GERDA by developing very pure materials for use nearby the detectors. Together, GERDA and \MJ\ have provided limits approaching $10^{26}$ yr. In this article, we elaborate on the historical use of Ge detectors for double beta decay addressing the strengths and weaknesses. We also summarize the status and future as many \MJ\ and GERDA collaborators have joined with scientists from other efforts to give birth to the LEGEND collaboration. LEGEND will exploit the best features of both experiments to extend the half-life limit beyond $10^{28}$ yr with a ton-scale experiment.
影响因子：
64.8
作者：
Agostini, M.;Allardt, M.;Zuzel, G.
通讯作者：
Zuzel, G.