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Development of High-Purity NaI(T1) Crystals for the SABRE Dark Matter Experiment

开发用于 SABRE 暗物质实验的高纯度 NaI(T1) 晶体

基本信息

批准号：
1620085
负责人：
Jay Benziger
金额：
$ 31.98万
依托单位：
Princeton University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2016
资助国家：
美国
起止时间：
2016-09-15 至 2022-09-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1620085&HistoricalAwards=false
关键词：
Development Purity NaI T1 Crystals

项目摘要

Multiple astronomical observations have established that about 85% of the matter in the universe is not made of normal atoms, but must be otherwise undetected elementary "dark matter" particles that do not emit or absorb light. Deciphering the nature of this so-called Dark Matter is of fundamental importance to cosmology, astrophysics, and high-energy particle physics. A leading hypothesis is that it is comprised of Weakly Interacting Massive Particles, or WIMPs, that were produced moments after the Big Bang. If WIMPs are the dark matter, then their presence in our galaxy may be detectable via scattering from atomic nuclei in detectors located deep underground to help reject backgrounds due to cosmic rays. Detection of WIMP dark matter would solve a fundamental mystery in particle physics and cosmology, providing a unique window to learning about the primary matter constituent of the Universe and of physics beyond the Standard Model of particle physics. SABRE (Sodium-iodide with Active Background REjection) is an experiment that will search for dark matter signals using an array of Sodium Iodide (NaI) scintillating crystals. This award will provide funds to demonstrate the feasibility of fabricating ultra-low background NaI crystals, with lower levels of Potassium-40 and other radioactive impurities, by improving the methods to produce and purify NaI powder, and by developing methods to grow crystals with very low contamination of radioactive elements. The SABRE project provides ample opportunities for students and postdoctoral researchers to gain experience and training for careers in basic research. SABRE has promoted strong relationships with commercial companies and assisted in the development of special products available to all customers. These collaborations have brought improved high purity products and sensitive assay services to the market. The development of high purity NaI crystals is also making possible other new experiments with scintillating bolometers for dark matter research.The sensitivity of the search for rare dark matter events depends critically on the background in the detector, which in NaI(Tl) crystals is dominated by low levels of K-40 radioactivity in the crystal. This award will support on-going development of NaI(Tl) crystals with lower intrinsic radioactivity. In addition, by coupling efficient low background photomultipliers to the crystals and reducing dynode afterglow with lower PMT voltage, they will achieve a threshold energy lower than that of the DAMA experiment. Their goal is a flat background of ~ 0.10 cpd/kg/keV and a threshold energy less than 1 keVee. Measurements of K at the level of 10 ppb have been possible for some time; an improvement to 2 ppb is indicated in recent work. A preliminary measurement of U and Th at a level of ~ 0.5 ppt is indicated in recent work. These measurements are much faster than growing crystal and gamma counting and are thus guiding research in a timely way toward production of crystals with low levels of these radioactive impurities.

多项天文观测已经证实，宇宙中约85%的物质不是由正常原子组成，而是必须是不发射或吸收光线的、未被探测到的原生“暗物质”粒子。破译这种所谓的暗物质的本质对宇宙学、天体物理学和高能粒子物理学具有根本的重要性。一个主要的假设是，它是由相互作用很弱的大质量粒子组成的，这些粒子是在大爆炸后不久产生的。如果WIMP是暗物质，那么它们在我们银河系中的存在可能是通过位于地下深处的探测器中原子核的散射来检测到的，以帮助排除宇宙射线的背景。WIMP暗物质的发现将解开粒子物理学和宇宙学中的一个基本谜团，为了解宇宙的主要物质组成和超越粒子物理标准模型的物理学提供了一个独特的窗口。SABRE(具有活性背景抑制的碘化钠)是一个使用碘化钠(NaI)闪烁晶体阵列来搜索暗物质信号的实验。该奖项将提供资金，通过改进生产和提纯NaI粉末的方法，以及开发生长放射性元素污染非常低的晶体的方法，展示制造具有较低水平的K-40和其他放射性杂质的超低本底NaI晶体的可行性。SABRE项目为学生和博士后研究人员提供了大量机会，为基础研究领域的职业生涯获得经验和培训。Sabre促进了与商业公司的牢固关系，并协助开发可供所有客户使用的特殊产品。这些合作为市场带来了改进的高纯度产品和灵敏的检测服务。高纯度NaI晶体的发展也使得使用闪烁测辐射热计进行暗物质研究的其他新实验成为可能。寻找稀有暗物质事件的灵敏度严重依赖于探测器中的背景，在NaI(Tl)晶体中，这是由晶体中低水平的K-40放射性控制的。该奖项将支持正在进行的本征放射性较低的NaI(Tl)晶体的开发。此外，通过将高效的低本底光电倍增管耦合到晶体上，并在较低的PMT电压下减少动态正极余辉，它们将获得比DAMA实验更低的阈值能量。他们的目标是大约0.10cpd/kg/kev的平坦本底和低于1keVee的阈值能量。钾的测量在10 ppb的水平已经可能有一段时间了；最近的工作表明，K的水平有了改进，达到2 ppb。最近的工作表明，U和Th的初步测量水平为~0.5ppt。这些测量比晶体生长和伽马计数快得多，从而及时指导研究，以生产这些放射性杂质水平较低的晶体。

项目成果

期刊论文数量（14）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Dark matter search with the SABRE experiment

通过 SABRE 实验寻找暗物质

DOI：
10.1088/1742-6596/1342/1/012060
发表时间：
2020
期刊：
Journal of Physics: Conference Series
影响因子：
0
作者：
D’Imperio, Giulia
通讯作者：
D’Imperio, Giulia

The SABRE project and the SABRE Proof-of-Principle

DOI：
10.1140/epjc/s10052-019-6860-y
发表时间：
2019-04-26
期刊：
EUROPEAN PHYSICAL JOURNAL C
影响因子：
4.4
作者：
Antonello, M.;Barberio, E.;Xu, J.
通讯作者：
Xu, J.

SABRE: WIMP modulation detection in the northern and southern hemisphere

SABRE：北半球和南半球的 WIMP 调制检测

DOI：
10.1088/1742-6596/718/4/042021
发表时间：
2016
期刊：
Journal of Physics: Conference Series
影响因子：
0
作者：
Froborg, F
通讯作者：
Froborg, F

The SABRE experiment

军刀实验

DOI：
10.1142/s0217751x22400164
发表时间：
2022
期刊：
International Journal of Modern Physics A
影响因子：
1.6
作者：
Zani, A.;D’Angelo, D.;Vignoli, C.;Di Carlo, G.;Di Giacinto, A.;Ianni, A.;Orlandi, D.;Mariani, A.;Copello, S.;Tomei, C.
通讯作者：
Tomei, C.

High sensitivity characterization of an ultrahigh purity NaI(Tl) crystal scintillator with the SABRE proof-of-principle detector

使用 SABRE 原理验证探测器对超高纯度 NaI(Tl) 晶体闪烁体进行高灵敏度表征

DOI：
10.1103/physrevd.104.l021302
发表时间：
2021
期刊：
Physical Review D
影响因子：
5
作者：
Calaprice, F.;Copello, S.;Dafinei, I.;D’Angelo, D.;D’Imperio, G.;Di Carlo, G.;Diemoz, M.;Di Giacinto, A.;Di Ludovico, A.;Ianni, A.
通讯作者：
Ianni, A.