Study of a zirconium getter for purification of xenon gas

TL;DR

This study evaluates the effectiveness of a zirconium getter in purifying xenon gas by measuring its ability to remove oxygen, nitrogen, and methane impurities at high pressure, revealing high purification efficiency for O2 and N2 but variable results for methane.

Contribution

It provides detailed measurements of impurity removal efficiencies and identifies operational factors affecting purifier performance in xenon gas purification.

Findings

Oxygen and nitrogen impurities are reduced to below 120 and 950 parts per trillion, respectively.

Methane removal efficiency varies significantly with purifier temperature and flow rate.

The purifier's capacity for methane can be exhausted before oxygen performance declines.

Abstract

Oxygen, nitrogen and methane purification efficiencies for a common zirconium getter are measured in 1050 Torr of xenon gas. Starting with impurity concentrations near 10^{-6} g/g, the outlet impurity level is found to be less than 120*10^{-12} g/g for O2 and less than 950*10^{-12} g/g for N2. For methane we find residual contamination of the purified gas at concentrations varying over three orders of magnitude, depending on the purifier temperature and the gas flow rate. A slight reduction in the purifier's methane efficiency is observed after 13 mg of this impurity has been absorbed, which we attribute to partial exhaustion of the purifier's capacity for this species. We also find that the purifier's ability to absorb N2 and methane can be extinguished long before any decrease in O2 performance is observed, and slower flow rates should be employed for xenon purification due to the cooling effect that the heavy gas has on the getter.