A Regenerable Filter for Liquid Argon Purification

TL;DR

This paper presents a regenerable filter system for liquid argon purification, achieving extremely low impurity levels and enabling in-situ regeneration, which enhances the efficiency and sustainability of liquid argon purification processes.

Contribution

The paper introduces a novel regenerable filter combining molecular sieve and activated copper-coated alumina for ultra-pure liquid argon purification.

Findings

Achieves impurity levels below 30 ppt of oxygen-equivalent impurities.

Enables in-situ regeneration of the filter at 250°C.

Maintains electron drift lifetime of at least 10 ms.

Abstract

A filter system for removing electronegative impurities from liquid argon is described. The active components of the filter are adsorbing molecular sieve and activated-copper-coated alumina granules. The system is capable of purifying liquid argon to an oxygen-equivalent impurity concentration of better than 30 parts per trillion, corresponding to an electron drift lifetime of at least 10 ms. Reduction reactions that occur at about 250 degrees Celsius allow the filter material to be regenerated in-situ through a simple procedure. In the following work we describe the filter design, performance, and regeneration process.