The Cryogenic System for the Panda-X Dark Matter Search Experiment

TL;DR

This paper describes the design and implementation of a cryogenic system for the Panda-X dark matter detector, emphasizing reliability, scalability, and efficient cooling for large-scale liquid xenon experiments.

Contribution

It presents a cryogenic system tailored for large-scale liquid xenon detectors, highlighting innovations in cooling efficiency and system reliability for dark matter searches.

Findings

Cooling power of 82W after thermal losses

Recirculation speed of 35 SLPM with 95.2% heat exchanger efficiency

System capable of scaling to ton-scale detectors

Abstract

Panda-X is a liquid xenon dual-phase detector for the Dark Matter Search. The first modestly-sized module will soon be installed in the China JinPing Deep Underground Laboratory in Sichuan province, P.R. China. The cryogenics system is designed to handle much larger detectors, even the final version in the ton scale. Special attention has been paid to the reliability, serviceability, and adaptability to the requirements of a growing experiment. The system is cooled by a single Iwatani PC150 Pulse Tube Refrigerator. After subtracting all thermal losses, the remaining cooling power is still 82W. The fill speed was 9 SLPM, but could be boosted by LN2 assisted cooling to 40 SLPM. For the continuous recirculation and purification through a hot getter, a heat exchanger was employed to reduce the required cooling power. The recirculation speed is limited to 35 SLPM by the gas pump. At this speed, recirculation only adds 18.5 W to the heat load of the system, corresponding to a 95.2 % efficiency of the heat exchanger.