Abstract We propose a method using a permeable membrane to separate Ne from Ar for Ne isotope analyses in a future planetary exploration, in particular, for the Martian surface. The results of simulation based on permeation data and theoretical formulas show that significant amounts of 20Ne without 40Ar permeate through Viton (fluoropolymer elastomer) and Kapton (polyimide) with appropriate thicknesses. Considering the simulation results, the amounts of 20Ne and 40Ar that permeate through 1 mm-thick Viton and 125 μm-thick Kapton were determined experimentally. The amounts of permeated 20Ne agree with those of 20Ne obtained by the theoretical calculation within experimental uncertainties. The amounts of permeated 40Ar are as small as those of the background, which is also consistent with the fact that the calculated amounts of 40Ar through those membranes are several orders of magnitude lower than the background 40Ar. In the present experiments, 20Ne/40Ar ratios increased up to 1 for Viton and 200 for Kapton from the terrestrial atmospheric ratio of 1.8 × 10−3 after permeation for 30 and 60 min, respectively. A Kapton sheet efficiently enhances the 20Ne/40Ar ratio and enables measurement of the Ne isotope composition without the significant 40Ar++ interference in planetary exploration. Assuming the Martian atmospheric pressure (7 hPa) and composition (2.3 ppm for 20Ne and 1.9% for 40Ar), the amounts of 20Ne and 40Ar that permeate through Kapton were calculated. The 20Ne/40Ar ratio can be increased up to ca. 1 using 75 μm-thick Kapton with a duration time of 30–60 min, where the contribution of 40Ar++ is approximately 10% of 20Ne+ and the uncertainty after the 40Ar++ correction is estimated to be a few percent. An effective area of 50 cm2 is required if the sensitivity of the QMS used in this study is assumed.

中文翻译：

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Ne-Ar 分离使用可渗透膜测量 Ne 同位素，用于未来的行星探索

摘要 我们提出了一种使用渗透膜将 Ne 与 Ar 分离的方法，以便在未来的行星探索中进行 Ne 同位素分析，特别是对火星表面的探测。基于渗透数据和理论公式的模拟结果表明，大量 20Ne 没有 40Ar 渗透通过具有适当厚度的 Viton（含氟聚合物弹性体）和 Kapton（聚酰亚胺）。考虑到模拟结果，通过 1 mm 厚的 Viton 和 125 μm 厚的 Kapton 渗透的 20Ne 和 40Ar 的量是通过实验确定的。在实验不确定性范围内，渗透的 20Ne 量与通过理论计算获得的 20Ne 量一致。渗透的 40Ar 量与背景量一样小，这也与通过这些膜计算出的 40Ar 量比背景 40Ar 低几个数量级的事实一致。在本实验中，在渗透 30 分钟和 60 分钟后，20Ne/40Ar 比率分别从地球大气比率 1.8 × 10−3 增加到 Viton 的 1 和 Kapton 的 200。Kapton 片有效地提高了 20Ne/40Ar 的比率，并能够测量 Ne 同位素组成，而不会在行星探索中受到 40Ar++ 的显着干扰。假设火星大气压力 (7 hPa) 和成分（20Ne 为 2.3 ppm，40Ar 为 1.9%），计算渗透通过 Kapton 的 20Ne 和 40Ar 的量。20Ne/40Ar 的比率可以增加到大约。1 使用 75 μm 厚的 Kapton，持续时间为 30-60 分钟，其中 40Ar++ 的贡献约为 20Ne+ 的 10%，40Ar++ 校正后的不确定性估计为几个百分点。如果假设本研究中使用的 QMS 具有灵敏度，则需要 50 cm2 的有效面积。