  In order to recuperate the ultra-high purity xenon from PandaX-4T dark matter
detector to high-pressure gas cylinders in emergency or at the end-of-run
situation, a high speed ultra-high purity xenon recuperation system is designed
and developed. This system includes a diaphragm pump, the heat management
system, the main recuperation pipeline, the reflux pipeline, the auxiliary
recuperation pipeline and the automatic control system. The liquid xenon in the
detector is vaporized by the heat management system, and the gaseous xenon is
compressed to 6 MPa at the flow rate of 200 standard litres per minute (SLPM)
using the diaphragm compressor. The high-pressure xenon is filled into 128 gas
cylinders via the main recuperation pipeline. During the recuperation, the low
pressure and temperature conditions of 2 ~ 3 atmospheres and 178 ~ 186.5 K in
PandaX-4T dark matter detector are kept by the cooperation of the main
recuperation pipeline, reflux pipeline and the auxiliary recuperation pipeline
to guarantee the safety, and the purity of the recuperated xenon gas is
measured to ensure no contamination happened. The development of the high speed
ultra-high purity xenon recuperation system is important for the operation of
large-scale dark matter detectors with the requirements of strict temperature
and pressure environment and low background.
