Diffusion in Crystalline Ice Measured Using Laser Resonant Desorption Techniques

该研究项目由分析和表面化学计划支持，解决了冰样品中杂质分析和扩散的问题。 Steven M.科罗拉多大学的乔治和他的同事们将激光共振解吸深度剖面法应用于非均匀大气化学和冰芯分析中重要物种的分析。 特别是，卤化氢，硝酸，各种阳离子，含硫分子，弱酸和弱碱在大气化学过程中所涉及的是本次调查的主题。 使用内部高压分析室，加上装载锁系统，使环境冰样品的分析，这些杂质的位置和扩散在一系列的冰样品正在检查。 这项工作的结果是显着的重要性，包括非均质过程的准确的大气模式的发展，以及了解冰川冰芯和他们的历史记录的环境条件。 对臭氧消耗和全球变暖等环境过程的了解依赖于对大气冰样和冰川冰芯中微量分子的位置和运动进行详细测量的可用性。 该研究项目的工作重点是开发高空间分辨率的激光解吸方法，以准确和精确地分析这些环境冰样品。 这项工作的结果对于我们不断发展对大气的理解至关重要，无论是在当今时代还是在地球的地质历史上。

This research project, supported by the Analytical and Surface Chemistry Program, addresses the question of impurity analysis and diffusion in ice samples. Professor Steven M. George and his colleagues at the University of Colorado apply laser resonant desorption depth profiling methods to the analysis of species important in heterogeneous atmospheric chemistry and ice core analysis. In particular, hydrogen halides, nitric acid, various cations, sulfur containing molecules, and weak acids and bases implicated in atmospheric chemical processes are the subject of this investigation. Using an internal high pressure analysis cell, coupled with a load lock system to enable the analysis of environmental ice samples, the location and diffusion of these impurities in a range of ice samples are being examined. The results of this work are of significant importance to the development of accurate atmospheric models which include heterogeneous processes, as well as to the understanding of glacial ice cores and their historical record of environmental conditions. The understanding of environmental processes such as ozone depletion and global warming rely on the availability of detailed measurements of the location and motion of trace molecules in atmospheric ice samples and in glacial ice cores. The work of this research project is focussed on developing high spatial resolution laser desorption methods for the accurate and precise analysis of these sorts of environmental ice samples. The results of this work are crucial to our developing understanding of the atmosphere, both in current times and across the geological history of the earth.