Liquid Argon Detector Calibration R&D for Dark Matter and Neutrino Physics

液氩检测器校准 R

• 批准号: ST/K002570/1
• 负责人: Jocelyn Monroe
• 金额: $ 18.8万
• 依托单位: Royal Holloway University of London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FK002570%2F1
• 关键词: Liquid; Argon; Detector; Calibration; R&D

This proposal is for R&D to improve the performance of experiments testing the fundamental symmetries of nature using neutrinos and searching for interactions of the mysterious dark matter that makes up most of the matter in the universe. Particle physics seeks to understand the nature of matter at the smallest scales and relate that knowledge to the behaviour of the universe at the largest scales. One of the main questions being addressed by experiments today is why the universe is made of matter and not antimatter. The standard model of particle physics links conservation laws with fundamental symmetries: the missing antimatter is connected to the violation of charge-parity (CP) symmetry---which says that the laws of nature should be the same for matter and for antimatter seen through a parity inversion, equivalent to looking at something upside down in a mirror. All known instances of CP violation are too small to account for the lack of antimatter, so experimenters are now searching for the origin of this using the elusive neutrino. Astronomical observations have shown us definitively that the matter we see makes up only a small fraction of the universe---just 5%! A significant fraction, 25%, is made up of enigmatic dark matter: massive particles that do not interact with light but do influence the world around us. The standard models of particle physics and cosmology predict that these dark matter particles obey the same laws of nature that normal matter does and so we can devise laboratory experiments to detect evidence of their presence. The leading theory is that dark matter is made up of heavy particles that interact via the weak nuclear force, just like neutrinos do. If so, then it should leave characteristic traces in terrestrial matter: atomic nuclei struck by dark matter particles will recoil with tiny amounts of energy. To test this hypothesis we build experiments designed to observe these tiny recoil energies. Because the rate of these interactions is small, and the recoil energy is tiny, we must build experiments at the cutting edge of particle detection technology to search for this weak signal. Many dark matter and neutrino experiments use cryogenic (very cold) noble liquids, such as liquid neon, argon or xenon, because of their stable atoms and excellent optical properties. In particular, these liquids emit large amounts of light when the dark matter particles cause nuclear recoils, and that light can be collected and interpreted readily to identify the type of particle that created it: nuclear recoil signal or an interaction of background radiation. Cryogenic noble liquid detector development is pushing the boundaries of particle detection, in a world-wide technology race to study the fundamental questions of the nature of neutrinos and dark matter. However the properties of light in these liquids is not very well understood, and therefore experiments must develop systems to initiate controlled "signals" inside the detectors that test the ability of the experiment to observe the signal, distinguish it from backgrounds and measure its energy correctly. This process is called detector calibration and it is where experimenters spend much of their effort. This proposal is to develop new technology for detector calibration and to make measurements of the optical properties of cold liquid argon, neon and xenon. Specifically, we will measure the attenuation lengths of light in these liquids; we will measure the angles that light is scattered into from the wavelength shifting films that must be used in cold liquids; and we will test the mechanical utility of certain designs for calibration devices. Once these measurements are made, the calibration of large, liquid noble detectors will be significantly improved, and we will be one step closer to identifying the nature of the puzzling dark matter that accounts for 25% of the universe, and understanding the mystery of the missing antimatter.

这项提议是为了提高使用中微子测试自然基本对称性的实验的性能，并寻找构成宇宙中大部分物质的神秘暗物质的相互作用。粒子物理学试图在最小尺度上理解物质的本质，并将这些知识与宇宙在最大尺度上的行为联系起来。今天实验要解决的主要问题之一是为什么宇宙是由物质而不是反物质组成的。粒子物理学的标准模型将守恒定律与基本对称性联系起来：缺失的反物质与电荷宇称（CP）对称性的违反有关--这意味着自然定律对于物质和反物质应该是相同的通过宇称反转，相当于在镜子里上下颠倒地看东西。所有已知的CP破坏的例子都太小，无法解释反物质的缺乏，所以实验人员现在正在使用难以捉摸的中微子来寻找这种情况的起源。天文观测已经明确地告诉我们，我们所看到的物质只占宇宙的一小部分-仅仅5%！很大一部分，25%，是由神秘的暗物质组成的：大质量的粒子不与光相互作用，但确实影响着我们周围的世界。粒子物理学和宇宙学的标准模型预测，这些暗物质粒子遵循与正常物质相同的自然定律，因此我们可以设计实验室实验来检测它们存在的证据。主流理论认为，暗物质是由重粒子组成的，它们通过弱核力相互作用，就像中微子一样。如果是这样的话，那么它应该会在地球物质中留下特征性的痕迹：被暗物质粒子撞击的原子核会以微小的能量反冲。为了验证这一假设，我们建立了旨在观察这些微小的反冲能量的实验。由于这些相互作用的速率很小，反冲能量很小，我们必须在粒子探测技术的前沿建立实验来寻找这种微弱的信号。许多暗物质和中微子实验使用低温（非常冷）稀有液体，如液态氖，氩或氙，因为它们具有稳定的原子和优异的光学性质。特别是，当暗物质粒子引起核反冲时，这些液体会发出大量的光，并且可以很容易地收集和解释这些光，以识别产生它的粒子类型：核反冲信号或背景辐射的相互作用。低温惰性液体探测器的发展正在推动粒子探测的边界，在世界范围内的技术竞赛，以研究中微子和暗物质的性质的基本问题。然而，这些液体中的光的性质还不是很清楚，因此实验必须开发系统来启动检测器内的受控“信号”，以测试实验观察信号的能力，将其与背景区分开来并正确测量其能量。这个过程被称为探测器校准，这是实验者花费大量精力的地方。本项目的目的是发展新的探测器校准技术，并对冷态液态氩、氖和氙的光学性质进行测量。具体来说，我们将测量光在这些液体中的衰减长度;我们将测量光从必须在冷液体中使用的波长偏移膜散射的角度;我们将测试某些校准设备设计的机械效用。一旦这些测量完成，大型液态探测器的校准将得到显著改善，我们将更接近于确定占宇宙25%的令人困惑的暗物质的性质，并了解失踪的反物质的奥秘。

项目成果

Design of the MiniCLEAN dark matter search veto detector subsystem

MiniCLEAN 暗物质搜索否决探测器子系统的设计

• DOI: 10.1016/j.nima.2015.01.028
• 发表时间: 2015
• 期刊: Accelerators, Spectrometers, Detectors and Associated Equipment
• 作者: Abruzzio R

Search for dark matter with a 231-day exposure of liquid argon using DEAP-3600 at SNOLAB

• DOI: 10.1103/physrevd.100.022004
• 发表时间: 2019-07-24
• 期刊: PHYSICAL REVIEW D
• 影响因子: 5
• 作者: Ajaj, R.;Amaudruz, P. -A.;Zuniga-Reyes, A.
• 通讯作者: Zuniga-Reyes, A.

First Direct Detection Constraints on Planck-Scale Mass Dark Matter with Multiple-Scatter Signatures Using the DEAP-3600 Detector

• DOI: 10.1103/physrevlett.128.011801
• 发表时间: 2022-01-07
• 期刊: PHYSICAL REVIEW LETTERS
• 影响因子: 8.6
• 作者: Adhikari, P.;Ajaj, R.;Zuniga-Reyes, A.
• 通讯作者: Zuniga-Reyes, A.

Precision Measurement of the Specific Activity of $^{39}$Ar in Atmospheric Argon with the DEAP-3600 Detector

使用 DEAP-3600 检测器精确测量大气氩气中 $^{39}$Ar 的比活度

• DOI: 10.48550/arxiv.2302.14639
• 发表时间: 2023
• 作者: Adhikari P

Constraints on dark matter-nucleon effective couplings in the presence of kinematically distinct halo substructures using the DEAP-3600 detector

• DOI: 10.1103/physrevd.102.082001
• 发表时间: 2020-05
• 期刊: Physical Review D
• 影响因子: 5
• 作者: P. Adhikari;R. Ajaj;D. Auty;C. E. Bina;W. Bonivento;M. Boulay;M. Cadeddu;B. Cai;M. C'ardenas-Montes-M.