Test of low radioactive molecular sieves for radon filtration in SF6 gas-based rare-event physics experiments. (21st June 2021)

• Record Type: Journal Article
• Authors: Marcelo Gregorio, R.R.; Spooner, N.J.C.; Berry, J.; Ezeribe, A.C.; Miuchi, K.; Ogawa, H.; Scarff, A.
• Is Part Of: Journal of instrumentation. Volume 16:Number 6(2021)
• Publication Date: 2021-06-21
• Subjects: Gas systems and purification -- Particle tracking detectors (Gaseous detectors); Scientific apparatus and instruments -- Periodicals; 502.84
• DOI: 10.1088/1748-0221/16/06/P06024
• Languages: English
• ISSNs: 1748-0221

Abstract

Abstract: Type 5 Å molecular sieves (MS) have been demonstrated to remove radon from SF6 gas. This is important for ultra-sensitive SF6 gas-based directional dark matter and related rare-event physics experiments, as radon can provide a source of unwanted background events. Unfortunately, commercially available sieves intrinsically emanate radon at levels not suitable for ultra-sensitive physics experiments. A method to produce a low radioactive MS has been developed in Nihon University (NU). In this work, we explore the feasibility of the NU-developed 5 Å type MS for use in such experiments. A comparison with a commercially available Sigma-Aldrich 5 Å type MS was made. The comparison was done by calculating a parameter indicating the amount of radon intrinsically emanated by the MS per unit radon captured from SF6 gas. The measurements were made using a specially adapted DURRIDGE RAD7 radon detector. The NU-developed 5 Å MS emanated radon up to 61 ± 9% less per radon captured (2.1 ± 0.1) × 10 −3, compared to the commercial Sigma-Aldrich MS (5.4 ± 0.4) × 10 −3, making it a better candidate for use in a radon filtration setup for future ultra-sensitive SF6 gas based experiments.