Xe isotopic fractionation in a cathodeless glow discharge. [for carbonaceous meteoritic composition studies
Xe isotopic fractionation in a cathodeless glow discharge. [for carbonaceous meteoritic composition studies
复制标题
无阴极辉光放电中的 Xe 同位素分馏。
DOI：
10.1016/0016-7037(86)90197-3
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
A. Fahey
中科院分区：
文献类型：
--
作者：
T. Bernatowicz;A. Fahey
我们报道了在20-40微米汞的稀薄空气中、在活性碳存在下和在空高温容器中进行无阴极辉光放电处理的Xe的同位素组成的结果。发现残余气相Xe和俘获Xe是分馏的。捕获的Xe成分被分馏到每Amu高达1%。我们提出了一个分馏过程的模型，在这个模型中，Xe离子同时被注入和从衬底材料溅射，质量依赖于有利于重同位素在衬底中的保留。模型预测的分馏与实验数据的比较表明，整个分馏过程与M1质量有关。数据似乎也倾向于注入依赖于M1，而溅射过程不依赖于质量，尽管这一结论不那么可靠。结果表明，产生Xe分馏不需要碳质材料的等离子体合成，以前的合成实验中观察到的分馏很可能是由于离子注入合成的材料。
We report results on the isotopic composition of Xe processed in cathodeless glow discharges in rarefied air at pressures of 20–40 microns Hg, in the presence of activated charcoal and in empty pyrex containers. Residual gas phase Xe and trapped Xe were found to be fractionated. The trapped Xe compositions were fractionated up to 1% per amu. We present a model for the fractionation process in which Xe ions are simultaneously implanted and sputtered from substrate material, with a mass dependence favoring retention of the heavy isotopes in the substrate. Comparison of the model predicted fractionations with the experimental data indicates an m1 mass dependence for the overall fractionation process. The data also seem to favor an m1 dependence for the implantation and no mass dependence for the sputtering process, although this conclusion is less secure. The results show that plasma synthesis of carbonaceous material is unnecessary for producing Xe fractionations, and that the fractionations observed in previous synthesis experiments are likely due to implantation of ions into the synthesized material.