DarkSide-20k: A 20 tonne two-phase LAr TPC for direct dark matter detection at LNGS
DarkSide-20k: A 20 tonne two-phase LAr TPC for direct dark matter detection at LNGS
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DOI：
10.1140/epjp/i2018-11973-4
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发表时间：
2018-03-29
影响因子：
3.4
通讯作者：
Zuzel, G.
中科院分区：
文献类型：
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作者：
Aalseth, C. E.;Acerbi, F.;Zuzel, G.
在操作Darkside-50探测器的成功经验的基础上，Darkside合作将建造Darkside-20k，这是一种使用两相液体Ar时间投影室(LAR TPC)的直接WIMP搜索探测器，有源(基准)质量为23t(20t)。本文描述了实验的初步设计，其中Darkside-20k LAR TPC部署在一个带有球形液体闪烁体否决权(LSV)的盾牌/否决权内，在圆柱形水切伦科夫否决权(WCV)中。这一初步设计为实验实现其物理目标提供了基线，而进一步的开发工作将导致探测器参数的最终优化和最终的技术设计。Darkside-50的运行表明，在应用脉冲形状分析之前，当使用从地下来源提取的Ar-39本底时，主要的Ar-39本底大大减少。来自Darkside-50的数据，结合MC模拟和分析模型，表明区分电子和核反冲的拒绝因子>；3×10(9)是可行的。这与Lar TPC中否决权系统的使用和硅光电倍增管的使用一起，是解锁通往大Lar TPC探测器质量的路径的关键，同时维持一个实验，在该实验中，在计划的曝光期间，WIMP搜索区域内预计发生的事件少于0.1次(不包括v诱导的核反冲)。Darkside-20K将具有比现场测量更低的背景，对于质量为1TeV/c(2)(10TeV/c(2))的WIMP，给予1.2 x 10(-47)cm(2)(1.1 x 10(-46)cm(2))的WIMP-核子截面的灵敏度，这将在5年内实现，在没有任何仪器背景的情况下产生100吨的曝光。
Building on the successful experience in operating the DarkSide-50 detector, the DarkSide Collaboration is going to construct DarkSide-20k, a direct WIMP search detector using a two-phase Liquid Argon Time Projection Chamber (LAr TPC) with an active (fiducial) mass of 23t (20t). This paper describes a preliminary design for the experiment, in which the DarkSide-20k LAr TPC is deployed within a shield/veto with a spherical Liquid Scintillator Veto (LSV) inside a cylindrical Water Cherenkov Veto (WCV). This preliminary design provides a baseline for the experiment to achieve its physics goals, while further development work will lead to the final optimization of the detector parameters and an eventual technical design. Operation of DarkSide-50 demonstrated a major reduction in the dominant Ar-39 background when using argon extracted from an underground source, before applying pulse shape analysis. Data from DarkSide-50, in combination with MC simulation and analytical modeling, shows that a rejection factor for discrimination between electron and nuclear recoils of > 3 x 10(9) is achievable. This, along with the use of the veto system and utilizing silicon photomultipliers in the LAr TPC, are the keys to unlocking the path to large LAr TPC detector masses, while maintaining an experiment in which less than < 0.1 events (other than v-induced nuclear recoils) is expected to occur within the WIMP search region during the planned exposure. DarkSide-20k will have ultra-low backgrounds than can be measured in situ, giving sensitivity to WIMP-nucleon cross sections of 1.2 x 10(-47) cm(2) (1.1 x 10(-46) cm(2)) for WIMPs of 1 TeV/c(2) (10 TeV/c(2)) mass, to be achieved during a 5yr run producing an exposure of 100 t yr free from any instrumental background.