A simple high-sensitivity technique for purity analysis of xenon gas

TL;DR

This paper introduces a highly sensitive method for analyzing the purity of xenon gas, significantly improving detection limits for impurities using a cold trap and mass spectrometry.

Contribution

The authors develop a simple, high-sensitivity technique for xenon purity analysis that enhances detection capabilities by a factor of 10,000 over previous methods.

Findings

Detection limits of 1 ppb for N2

Detection limits of 160 ppt for O2

Detection limits of 60 ppt for methane

Abstract

We report on the development and performance of a high-sensitivity purity-analysis technique for gaseous xenon. The gas is sampled at macroscopic pressure from the system of interest using a UHV leak valve. The xenon present in the sample is removed with a liquid-nitrogen cold trap, and the remaining impurities are observed with a standard vacuum mass-spectroscopy device. Using calibrated samples of xenon gas spiked with known levels of impurities, we find that the minimum detectable levels of N2, O2, and methane are 1 ppb, 160 ppt, and 60 ppt respectively. This represents an improvement of about a factor of 10,000 compared to measurements performed without a coldtrap.