The EXO-200 detector, part II: Auxiliary Systems

TL;DR

This paper details the design and performance of auxiliary systems for the EXO-200 liquid xenon detector, focusing on cryogenics, xenon handling, and controls to ensure detector safety, purity, and thermal stability.

Contribution

It introduces novel auxiliary system features tailored for the EXO-200 detector's specific needs, enhancing its operational reliability and performance.

Findings

Successful implementation of cryogenic and xenon handling systems

Achievement of high chemical purity of xenon

Maintenance of thermal uniformity across the detector

Abstract

The EXO-200 experiment searched for neutrinoless double-beta decay of $^{136}$Xe with a single-phase liquid xenon detector. It used an active mass of 110 kg of 80.6%-enriched liquid xenon in an ultra-low background time projection chamber with ionization and scintillation detection and readout. This paper describes the design and performance of the various support systems necessary for detector operation, including cryogenics, xenon handling, and controls. Novel features of the system were driven by the need to protect the thin-walled detector chamber containing the liquid xenon, to achieve high chemical purity of the Xe, and to maintain thermal uniformity across the detector.