Test of low radioactive molecular sieves for radon filtration in SF6 gas-based rare-event physics experiments
Test of low radioactive molecular sieves for radon filtration in SF6 gas-based rare-event physics experiments
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DOI：
10.1088/1748-0221/16/06/p06024
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发表时间：
2020-11
影响因子：
1.3
通讯作者：
R.R. Marcelo Gregorio;N. Spooner;J. Berry;A. Ezeribe;K. Miuchi;H. Ogawa;A. Scarff
中科院分区：
文献类型：
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作者：
R.R. Marcelo Gregorio;N. Spooner;J. Berry;A. Ezeribe;K. Miuchi;H. Ogawa;A. Scarff
5型分子筛（MS）已被证明可以从SF6气体中去除氡。这对于超灵敏的SF6气体定向暗物质和相关的稀有事件物理实验非常重要，因为氡可以提供不需要的背景事件的来源。不幸的是，商业上可获得的筛本质上散发出不适合超灵敏物理实验的水平的氡。日本大学（NU）开发了一种生产低放射性MS的方法。在这项工作中，我们探讨了在这样的实验中使用的NU开发的5 μ m型MS的可行性。与市售的Sigma-Aldrich 5 μ m型MS进行比较。通过计算一个参数来进行比较，该参数指示从SF6气体捕获的每单位氡由MS固有地散发的氡的量。测量是使用一个专门改装的DURRIDGE RAD 7氡探测器。与商用的Sigma-Aldrich MS（5.4 ± 0.4）× 10 − 3相比，NU开发的5 μ m MS每捕获（2.1 ± 0.1）× 10 − 3的氡释放量减少了61 ± 9%，使其成为未来超灵敏SF6气体实验的氡过滤装置的更好候选者。
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.