Magnetically-coupled piston pump for high-purity gas applications

TL;DR

This paper introduces a custom magnetically-coupled piston pump designed for high-purity noble gas applications, achieving high flow rates and low contamination suitable for sensitive radiation detection experiments.

Contribution

A novel hermetically sealed, low-Rn-emanating pump with magnetic coupling that meets radiopurity and performance requirements for noble gas detectors.

Findings

Achieves over 210 slpm with argon

Delivers more than 170 slpm with xenon

Maintains up to 1.9 bar compression

Abstract

Experiments based on noble elements such as gaseous or liquid argon or xenon utilize the ionization and scintillation properties of the target materials to detect radiation-induced recoils. A requirement for high light and charge yields is to reduce electronegative impurities well below the ppb level. To achieve this, the target material is continuously circulated in the gas phase through a purifier and returned to the detector. Additionally, the low backgrounds necessary dictate low-Rn-emanation rates from all components that contact the gas. Since commercial pumps often introduce electronegative impurities from lubricants on internal components or through small air leaks, and are not designed to meet the radiopurity requirements, custom-built pumps are an advantageous alternative. A new pump has been developed in Muenster in cooperation with the nEXO group at Stanford University and the nEXO/XENON group at Rensselaer Polytechnic Institute based on a magnetically-coupled piston in a hermetically sealed low-Rn-emanating vessel. This pump delivers high performance for noble gases, reaching more than 210 standard liters per minute (slpm) with argon and more than 170 slpm with xenon while maintaining a compression of up to 1.9 bar, demonstrating its capability for noble gas detectors and other applications requiring high standards of gas purity.