Operation Analysis of PandaX-4T Ultra-High Purity Xenon Cryogenic Distillation System for Removal of Krypton

Abstract

Based on the McCabe-Thiele (M-T) method and the conservation of mass and energy, the PandaX-4T collaboration group designs an efficient cryogenic distillation system to reduce the mole fraction of krypton in commercial xenon from 5×10-7 to 1×10-14. Since the ultra-high purity xenon cryogenic distillation system has completed the offline purification operation, it is necessary to conduct the corresponding operation analysis. Therefore, the stability and purification performance of the ultra-high purity xenon cryogenic distillation system are studied by analyzing the parameters such as temperature, pressure, flowrate, and mole faction of the product xenon in each operating stage. The PandaX-4T cryogenic distillation system has been operating stably for 1.5 m at a collection efficiency of 99% and a purification rate of 10 kg/h, and has purified 5.75 t of xenon. The experimental data show that the system is stable, safe, and reliable in all stages of operation, and the krypton concentration in product xenon is less than 7.99×10-12. The operation analysis of the PandaX-4T ultra-high purity xenon cryogenic distillation system has a theoretical research value and practical engineering significance, providing very important reference for optimization of distillation operation of the next stage.

Keywords

• cryogenic distillation
• ultra-high purity xenon
• krypton
• dark matter detection