Development of a Technique for Quantitative Hydrogen Analyses of Geological Materials Using SIMS

9975549 Hervig该奖项支持开发一种利用二次离子质谱（西姆斯）和离子注入技术对地质材料中的氢进行定量微量分析的技术。氢影响许多地质过程，包括岩石的熔化温度，导致火山爆发的气泡成核，以及矿物的强度。氢是含水矿物的重要结构成分，其羟基含量可作为矿物挥发性的指示剂。氢在名义上无水矿物中的存在代表了地幔中氢收支的重要部分。 建议的研究是必要的，因为在地质材料中的H的定量微量分析，现在不能没有获得一个标准非常接近的化学成分的未知。合成每种感兴趣的组合物的标准品是不可行的，并且没有直接的替代方案，因为不存在基于其他标准品预测校准的理论。将这项工作与西姆斯提供的高灵敏度和空间分辨率相结合，将使我们能够分析标准抛光薄切片中的各种地质相，我们可以使用这些薄切片来攻击许多研究领域，包括火山学，变质岩石学，低温地球化学和高压地球化学。由于这项技术开发的结果很容易从一个西姆斯交叉到另一个（同一制造商），我们的工作结果也将允许其他实验室的研究人员获得感兴趣阶段的定量氢分析。离子注入是一种可靠的定量方法，近二十年来一直应用于半导体分析问题;这项技术很容易转移到地质材料中。

9975549HervigThis award supports the development of a technique for the quantitative microanalysis of hydrogen in geological materials using secondary ion mass spectrometry (SIMS) and ion implantation. Hydrogen influences many geological processes, including melting temperatures of rocks, bubble nucleation leading to volcanic eruptions, and the strength of minerals. Hydrogen is an essential structural constituent of hydrous minerals, and their hydroxyl contents may provide an indicator of volatile activities. The presence of hydrogen in nominally anhydrous minerals represents an important part of the hydrogen budget in the earth's mantle. The proposed research is needed because quantitative microanalyses for H in geological materials cannot now be made without obtaining a standard very close in chemical composition to the unknown. It is not feasible to synthesize standards for every composition of interest and there is no straightforward alternative because no theory exists to predict the calibration based on other standards. Combining this work with the high sensitivity and spatial resolution provided by SIMS will allow us to analyze a wide range of geological phases in standard polished thin sections which we can use to attack many areas of research, including volcanology, metamorphic petrology, low-temperature geochemistry, and high pressure geochemistry. Because the result of this technique development will easily cross from one SIMS to another (of the same manufacturer), the results of our work will also allow researchers at other laboratories to obtain quantitative hydrogen analyses on phases of interest. Ion implantation is a reliable, quantitative method that has been applied to problems in semiconductor analysis for nearly two decades; this technology is readily transferred to geologic materials.***