暗物质探测器的液氙低温精馏系统研制

Design and Construction of a Cryogenic Distillation System of Liquid Xenon for Dark Matter Detector

针对暗物质探测器中降低介质液氙中放射性氪-85含量可获得高纯度氙的问题,通过Mc-Cabe-Thiele(M-T)法及质量、能量守恒,设计并研制出一种将氪从氙中提取出且可获得高纯度氙气的高效低温精馏系统.该精馏系统中的主要结构精馏塔采用填料塔形式,填料为高效新型规整填料PACK-13C,塔高4m,直径80mm,其中精馏段1.9m,提馏段2.1m.该精馏系统可以在回收率为99%的情况下,以5kg/h(15SLPM)的速率将氙中氪的含量从10-9降低到10-12,这对要求高精度、高灵敏度、低本底的大型暗物质探测器的研制至关重要.

To reduce the radio krypton 85 concentration in liquid xenon, which is one of the commendable detecting media for dark matter detection, an efficient cryogenic distillation system to remove the krypton from the commercially available xenon was specifically designed, developed and constructed by using the McCabe Thiele （M-T） method, mass conservation and energy conservation. The core of the distillation system is the packing tower which is 4 m high and 80 mm in diameter where a kind of efficient new structured packing PACK-13C was used. This distillation system can reduce the krypton in the xenon from 10^-9 to 10^-12 with 99%0 of Xe collection efficiency （i.e. , the amount of Xe rejected is only 1%） at a maximum flow rate of 5 kg/h 15SLPM）, which is crucial for the dark matter detector with a high sensitivity and low-background.