DEAP-3600 Operation and Analysis

DEAP-3600操作与分析

• 批准号: SAPPJ-2017-00028-3
• 负责人: Retiere, Fabrice
• 金额: $ 6.45万
• 依托单位: TRIUMF
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Project
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=617926
• 关键词: DEAP; 3600; Operation; Analysis

The DEAP collaboration has been vary active with detector construction completion, cooldown, filling with liquid argon, detector commissioning, data collection and analysis. Operation of the detector will continue through the period covered by this request, and will require significant collaboration effort, enabled by the requested funds. The origin of dark matter in our universe is currently one of the most important questions in particle astrophysics. It is well-established that most of the matter in our universe is dark. A favored hypothesis is that the dark matter consists of WIMPs, weakly interacting massive particles, which could be detected by observing their elastic scattering from nuclei. This proposal builds on research using liquid argon for a sensitive dark matter search. The current best limit on the spin-independent WIMP-nucleon cross-section is approximately 2.2x10^-46 cm^2 for a WIMP mass of 50 GeV, obtained by the LUX collaboration. Scaling the current-generation experiments to larger masses is critical since current theoretical models predict that improvements of sensitivity of several orders of magnitude may be needed before dark matter particles can be detected. Our research targets sensitivity to the WIMP-nucleon cross-section of 10^-46 cm^2 for a 100-GeV WIMP, and with good sensitivity to high-mass WIMPs. Noble liquids as low-energy particle astrophysics detectors have gained much interest since many of these can be cleaned to extremely low levels of radioactivity, and it is recognized that these can be used to build very large target mass detectors. Unique to the DEAP-3600 experiment is the novel technique of providing discrimination based on the time evolution of the scintillation pulse. This leads to a simple detector design that can be scaled to a very large target mass. The detector includes a large spherical acrylic vessel viewed by photomultiplier tubes (PMTs) to allow the recording of the evolution of a scintillation event in the argon. The PMT positions for each event will be used to estimate the initial event vertex, and serve as the primary rejection for external-source background events to allow a fiducial target mass of approximately 1000 kg of argon. The experiment resides in a large shielding tank approximately 8 meters in diameter and 8 meters high. Construction of the detector was completed in 2015, and the collaboration has been commissioning the detector systems and performing detector calibration, in preparation for the science run with liquid argon. This proposal will lead to further training of HQP in Canada. In addition to attracting students and international highly qualified researchers, it is anticipated that several post-doctoral fellows and RAs will be supported by the requested funds, in addition to technical personnel to enable operations at the experimental site.

DEAP在探测器建造完成、冷却、充氩气、探测器调试、数据收集和分析等方面的合作一直很活跃。探测器的运作将在本请求所涉期间继续进行，并将需要由所请求的资金提供的大量协作努力。暗物质在我们宇宙中的起源是目前粒子天体物理学中最重要的问题之一。众所周知，我们宇宙中的大部分物质都是黑暗的。一个受欢迎的假设是暗物质由弱相互作用的大质量粒子组成，可以通过观察它们从原子核的弹性散射来探测。这一建议建立在利用液态氩进行敏感暗物质搜索的基础上。目前由LUX合作获得的WIMP质量为50 GeV时，自旋无关的WIMP-核子截面的最佳极限约为2.2x10^-46 cm^2。将当前的实验规模扩大到更大的质量是至关重要的，因为目前的理论模型预测，在探测到暗物质粒子之前，可能需要将灵敏度提高几个数量级。我们的研究目标是对100-GeV WIMP的10^-46 cm^2的核子截面的灵敏度，并且对高质量WIMP具有良好的灵敏度。惰性液体作为低能粒子天体物理探测器已经获得了很大的兴趣，因为它们中的许多可以被清洗到极低的放射性水平，并且人们认识到这些可以用来建造非常大的目标质量探测器。DEAP-3600实验的独特之处在于，它采用了一种基于闪烁脉冲时间演变的新技术。这导致了一个简单的探测器设计，可以缩放到一个非常大的目标质量。探测器包括一个由光电倍增管（pmt）观察的大型球形丙烯酸容器，以记录氩气中闪烁事件的演变。每个事件的PMT位置将用于估计初始事件顶点，并作为对外部源背景事件的主要抑制，以允许大约1000千克氩气的基准目标质量。实验在直径约8米、高约8米的大型屏蔽槽内进行。探测器的建造于2015年完成，该合作组织一直在调试探测器系统并进行探测器校准，为用液态氩进行科学运行做准备。该提案将导致HQP在加拿大的进一步培训。除了吸引学生和国际高水平的研究人员外，预计所要求的资金将支持几名博士后研究员和研究人员，此外还有技术人员，以便在实验现场开展工作。