Development of noble gas/liquid detectors for neutrinoless double beta decay and dark matter searches

当今物理学中一些最引人注目的问题，例如发现暗物质粒子或通过无中微子双β衰变确定中微子质量尺度，只能通过对罕见过程敏感的大质量，低背景探测器来回答。 这种探测器必须由超纯材料制成，以尽量减少内部产生的背景，适当地屏蔽当地的实验环境的背景，并位于地下深处，以尽量减少来自宇宙射线诱导background. efforts的污染目前正在努力开发惰性气体/液体探测器利用电离诱导电荷和/或闪烁光作为检测机制。 这种探测器的中心目标，通常是液态或气态形式的氩或氙，可以很容易地净化，以将大多数背景降低到十亿分之几的水平。 检测器信号可以提供良好的能量分辨率和位置重构，使得能够显著抑制背景水平和有效识别信号事件。 拟议的研究将侧重于开发惰性气体/液体探测器技术，目的是设计和建造用于暗物质粒子和无中微子双β衰变搜索的大型探测器。 一个大规模的气体氙时间投影室（TPC）与闪烁光读出正在开发在卡尔顿与浓缩氙天文台（EXO）的合作。 目标是测量136氘的双β衰变谱，并寻找无中微子的双β衰变信号。将结合使用氩脉冲形状的暗物质实验（DEAP）开发用于暗物质搜索的液氩闪烁探测器。SNOLAB设施提供6000米水当量的宇宙射线屏蔽，是举办这两个实验的理想场所。

Some of the most compelling questions in present-day physics, such as discovering dark matter particles ordetermining the neutrino mass scale via neutrinoless double beta decay, can only be answered via large-mass, low-background detectors sensitive to rare processes at the level of tens of events/year.  Such detectors must be constructed from ultra-pure materials to minimize internally generated backgrounds, properly shielded from backgrounds local to the experimental environment, and located deep underground to minimize contamination from cosmic-ray induced backgrounds.Efforts are currently underway to develop noble gas/liquid detectors utilizing ionization induced charge and/or scintillation light as the detection mechanism.  The central target for such detectors, typically Argon or Xenon in liquid or gaseous form, can be readily purified to reduce most backgrounds to the parts per billion level.  The detector signals can provide good energy resolution and position reconstruction enabling significant suppression of background levels and efficient identification of signal events.  The proposed research will focus on the development of noble gas/liquid detector technology with the  aim of designing and constructing large-scale detectors for dark matter particle and neutrinoless double beta decay searches.  A large-scale gaseous Xenon time projection chamber (TPC) with scintillation light readout is being developed at Carleton with the Enriched Xenon Observatory (EXO) collaboration.  The goal here is to measure the double beta decay spectrum of 136Xe and search for a neutrinoless double beta decay signal. Development of a liquid argon scintillation detector for a dark matter search will be carried out in conjunction with the Dark Matter Experiment using Argon Pulse shapes (DEAP). The SNOLAB facility, providing 6000 meters water equivalent of cosmic-ray shielding, is the ideal site to host both of these experiments.