Improvements in noble gas separation methodology: A nude cryogenic trap

Abstract

A new noble gas cryogenic trap design employing polished stainless steel as the active trapping surface is described and tested. This trap offers significant advantages over the charcoal trap systems now commonly used for the preparation of noble gas samples for mass spectrometric analysis. Aliquots of Ne, Ar, Kr, and Xe are quantitatively trapped at less than 9 K and selectively released (≥99% at 20 K, 85 K, 110 K, 135 K, respectively). These release temperatures are significantly lower than obtained with conventional charcoal traps. The sorption-desorption characteristics of the trap for the individual gases and neon-argon mixtures are examined in detail as a function of trap temperature. The low release temperatures and improved separation for these noble gases will decrease processing times, reduce blanks and memory, and enhance the purity of noble gas sample preparation as compared to charcoal traps.