The Darkside Dark Matter Detector

在粒子物理学中，探测银河系暗物质并确定其基本性质是一个非常重要的任务。对大质量WIMP（弱相互作用大质量粒子）暗物质最灵敏的直接搜索是使用大型液态惰性气体探测器来搜索核反冲。我们目前的探测器DEAP-3600包含约3.3吨液态氩，是目前世界上最灵敏的氩暗物质探测器。该提案请求支持，使加拿大研究人员能够参与DS-20k探测器，这是一个大型液态氩时间投影室（TPC），将位于意大利格兰萨索实验室，将液态氩暗物质探测的范围扩大一个数量级。加拿大小组已经开始着手研究DarkSide-20k计划的几个方面，特别是在他们过去经验丰富的领域：数据采集系统和电子设备，地下氩气工厂和随后的存储和工艺，探测器的设计，加拿大丙烯酸制造的独特TPC，以及为TPC组件和TPB制造和涂覆丙烯酸的程序。与这些活动有关的主要资本费用将在单独的原讼法庭提案中提出。

The detection of galactic dark matter and the establishment of its fundamental properties are a very high priority in particle physics. The most sensitive direct searches for high mass WIMP (weakly interacting massive particle) dark matter use large liquid noble gas detectors to search for nuclear recoils. Our current detector, DEAP-3600 contains about 3.3 tonnes of liquid argon and is currently the most sensitive argon dark matter detector in the world. This proposal is requesting support to enable Canadian researchers to participate in the DS-20k detector, a large liquid argon time projection chamber(TPC) that will be situated in the Gran Sasso Laboratory in Italy that will extend the reach of liquid argon dark matter detection by an order of magnitude. Canadian groups have started to work on several aspects of the DarkSide-20k program, particularly in areas where they have strong past experience: the data acquisition system and electronics, the underground argon plant and subsequent storage and processes, the design of the detector, the unique TPC to be built from acrylic in Canada, and the procedures to fabricate and coat acrylic with resistive coatings for TPC components and with TPB for wavelength shifting. The main capital costs associated with these activities are being requested in a separate CFI proposal. The experiment in Italy is the result of a joining together of all the argon dark matter researchers in the world, to form a global argon dark matter collaboration. After the experiment in Italy is complete, the plan is to build an even larger detector of 400 tonnes (Argo) that will be located at the SNOLAB underground laboratory in Sudbury. The objective is to build on DEAP with a two-step program to reach down in sensitivity to the "Neutrino Floor" caused by atmospheric neutrinos coherently scattering in the detector and generating recoils that simulate WIMP dark matter. The light emission properties of liquid argon have already been demonstrated in DEAP to enable discrimination greater than 108 against other backgrounds such as radon and pp solar neutrinos at the Neutrino Floor. DarkSide-20k will have ultra-low backgrounds that can be measured in situ. This will give sensitivity to WIMP-nucleon cross sections of 1.2 10-47 cm2 (1.1 1046 cm2) for WIMPs of 1 TeV/c2 (10 TeV/c2) mass, to be achieved during a 5 year run producing an exposure of 100 tonne-year free from any instrumental background.