Electron probe microanalyzer with field emission gun

电子探针微量分析仪（EPMA）是固体物质研究中不可缺少的仪器，需要精确到亚微米范围的高空间分辨率的元素分布，以及精确到10µg/g范围的元素含量和检测限的化学定量。因此，电子探针分析不仅在地球科学研究中，而且在一般的材料研究中都是定量微米级分析的重要组成部分。在Göttingen大学的Geowissenschaftliche中心，几个工作组将微探针与大量其他元素和同位素分析方法结合使用：(a) EPMA方法对于获得非常精确的热气压测定结果是必不可少的。与许多其他分析方法相比，在合适的矿物反应相平衡系统中可以更准确地确定诸如温度、压力或氧逸度等密集参数。特别是，我们将在未来几年继续应用和扩展“单相温度计”。(b)为了从非平衡相系统确定地质时间速率，使用场发射阴极为分析较短的时间尺度或某些矿物反应中元素的缓慢扩散速率开辟了新的可能性。这项工作有助于理解依赖时间的过程，例如在岩浆系统中。实验将确定在选定的熔融或固态系统中的扩散速率。(c)由于传统电子束技术的横向分辨率低，迄今为止，对宇宙化学过程的一些氧化还原敏感过程的精确解释失败了。在这里，场发射阴极将有助于获得更好的结果。(d)我们利用某些矿物及其共生物的化学成分来推导它们在沉积体系中的物源。这使得重建全球地球动力学过程成为可能。(e)该装置用于考古研究：EPMA是分析历史玻璃和重建考古冶金过程的基本分析仪器。(f)地质档案是当前和今后研究项目的另一个重点。钙化海洋生物的不同元素条件作为气候档案，可以绘制温度变化或海洋覆盖时间变化的地图。应用带场发射源的电子探针可以提高定量微尺度分析的空间分辨率。具有灵敏分析晶体的仪器将使测量结果更加精确，可检测性更好。

The electron probe microanalyzer (EPMA) is an indispensable instrument in the investigation of solid matter, when precise element distributions with high spatial resolution down to the sub-micrometer range and exact chemical quantifications of the element contents and detection limits down to the lower 10 µg/g range are required. Electron microprobe analysis is thus an important component of quantitative micron-scaled analysis not only in geoscientific research, but also in materials research in general. At the Geowissenschaftliche Zentrum of the University of Göttingen, the microprobe is used by seveal working groups in combination with a large number of other elemental and isotopical analytical methods:(a) The EPMA methodology is indispensable for obtaining very precise results in thermo-barometry. Intensive parameters such as temperature, pressure or oxygen fugacity can be determined more accurately in suitable phase equilibrium systems of mineral reactions than with many other analytical methods. In particular, we will continue to apply and expand "single-phase thermometers" in the coming years. (b) In order to determine geological time rates from non-equilibrated phase systems, the use of a field emission cathode opens up new possibilities for the analysis of shorter time scales or slow diffusion rates of elements for selected mineral reactions. This work helps to understand time-dependent processes, for example in magmatic systems. Experiments will determine diffusion rates in selected melt or solid state systems.(c) The exact elucidation of some redox-sensitive processes of cosmochemical processes has so far failed due to the low lateral resolution of conventional electron beam technology. Here the field emission cathode will contribute to better results.(d) We use the chemical composition of certain minerals and their parageneses to derive their provenances in sedimentary systems. This allows to reconstruct global geodynamic processes.(e) The device is used in archaeometric research: The EPMA is an essential analytical instrument for the analysis of historical glass, as well as for archaeometallurgical process reconstruction.(f) Geological archives are another focus of current and future research projects. Varying elemental conditions of calcifying marine organisms serve as climate archives and can map temperature changes or changing duration of seaice cover. With the applied electron microprobe with field emission source we will achieve an improved spatial resolution of the quantitative micro-scale analysis. The equipment with sensitive analyzer crystals will lead to more precise measurement results and better detectability.