论文标题
Xenonnt的高流量去除系统的设计，构建和调试
Design, construction and commissioning of a high-flow radon removal system for XENONnT
论文作者
论文摘要
开发并构建了基于低温蒸馏的高流量去除系统，以减少液体氙气探测器中ra诱导的背景，以进行罕见的事件搜索，例如Xenonnt。需要连续纯化液体XENON库存为8.4吨的过程流动至71 kg/h（200 slpm），以使检测器内部的ra源减少ra缩小因子。为了达到如此高的流量，蒸馏柱的设计具有液体氙气入口和出口，以及具有高液化功能的新型定制浴室式热交换器。蒸馏过程是使用McCabe-thiele方法的修改而没有底部产品提取的。热力学概念基于带有相变介质的克劳西乌斯 - rankine冷却循环，在这种情况下为氙气本身。为了大幅度降低外部冷却能力的需求，开发了一种节能的热泵概念，该概念使用定制的四缸磁耦合活塞泵作为压缩机。蒸馏系统在热力学稳定的条件下以（91 $ \ pm $ 2）kg/h（（（258 $ \ pm $ 6）SLPM）的过程流动，比设计高30％。通过这种流程，给定测量的ra源分布，预计在Xenonnt检测器内预计$^{222} $ rn活动浓度<1 $μ$ bq/kg。
A high-flow radon removal system based on cryogenic distillation was developed and constructed to reduce radon-induced backgrounds in liquid xenon detectors for rare event searches such as XENONnT. A continuous purification of the XENONnT liquid xenon inventory of 8.4 tonnes at process flows up to 71 kg/h (200 slpm) is required to achieve a radon reduction by a factor two for radon sources inside the detector. To reach such high flows, the distillation column's design features liquid xenon inlet and outlets along with novel custom-made bath-type heat exchangers with high liquefaction capabilities. The distillation process was designed using a modification of the McCabe-Thiele approach without a bottom product extraction. The thermodynamic concept is based on a Clausius-Rankine cooling cycle with phase-changing medium, in this case the xenon itself. To drastically reduce the external cooling power requirements, an energy efficient heat pump concept was developed applying a custom-made four cylinder magnetically-coupled piston pump as compressor. The distillation system was operated at thermodynamically stable conditions at a process flow of (91$\pm$2) kg/h ((258$\pm$6) slpm), 30 % over design. With this flow, a $^{222}$Rn activity concentration <1 $μ$Bq/kg is expected inside the XENONnT detector given the measured radon source distribution.
