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e-Article

Chromatographic separation of radioactive noble gases from xenon
Document Type
article
Source
Subject
Nuclear and Plasma Physics
Synchrotrons and Accelerators
Physical Sciences
Xenon
Krypton
Adsorption
Chromatography
Gas Separation
Dark Matter
physics.ins-det
Astronomical and Space Sciences
Atomic
Molecular
Nuclear
Particle and Plasma Physics
Nuclear & Particles Physics
Astronomical sciences
Particle and high energy physics
Language
Abstract
The Large Underground Xenon (LUX) experiment operates at the Sanford Underground Research Facility to detect nuclear recoils from the hypothetical Weakly Interacting Massive Particles (WIMPs) on a liquid xenon target. Liquid xenon typically contains trace amounts of the noble radioactive isotopes 85Kr and 39Ar that are not removed by the in situ gas purification system. The decays of these isotopes at concentrations typical of research-grade xenon would be a dominant background for a WIMP search experiment. To remove these impurities from the liquid xenon, a chromatographic separation system based on adsorption on activated charcoal was built. 400 kg of xenon was processed, reducing the average concentration of krypton from 130 ppb to 3.5 ppt as measured by a cold-trap assisted mass spectroscopy system. A 50 kg batch spiked to 0.001 g/g of krypton was processed twice and reduced to an upper limit of 0.2 ppt.