Acquisition of a Scanning Electron Microscope at Yale Geology and Geophysics

这个合同将允许购买一台扫描电子显微镜(SEM)，该显微镜具有一系列高分辨率分析地球材料结构和成分的能力，包括生物样品。我们将购买的扫描电子显微镜是飞利浦XL30 ESEM-FEG，它具有场发射枪(FEG)和用于电子背散射衍射(EBSD)图案分析的软件/硬件包，可在低真空和高真空模式下运行。这一新设施对耶鲁地质和地球物理学的各种研究活动至关重要，这些活动包括：(1)实验和自然变形样品的变形微结构(Karato，Brandon)，(2)流体-岩石相互作用(Aogue，Rye)，(3)微生物地球化学和地球微生物(Blake)。由这种最先进的扫描电子显微镜附带的EBSD包提供的高空间分辨率的完整取向测量，对于Karato和Brandon对变形岩石的微观结构研究至关重要。这项技术在欧洲的地质应用很广泛，但在美国仅限于少数几个实验室。当FEG电子源与EBSD封装一起使用时，取向测量的空间分辨率接近0.25 mm。如此高的空间分辨率是至关重要的，特别是对于Karato小组的实验研究，其中高压条件下的微结构发展是使用非常细小的颗粒尺寸的样品来研究的。同样，在耶鲁大学地质学和地球物理学的几个研究领域，这种扫描电子显微镜的环境扫描模式具有重大优势。这包括通过电荷对比成像技术(在环境扫描电子显微镜模式下选择性地工作)研究流体-岩石相互作用，以及微生物地球化学和地质微生物学的研究，这需要矿物表面和相关微生物的高分辨率图像。在现有的分析和其他实验设施的基础上增加这一设施，将大大加强耶鲁大学地质和地球物理系的实验地球科学研究计划。

0216784KaratoThis award will permit the purchase of a scanning electron microscope (SEM) with a range of capabilities for high-resolution analyses of structures and compositions of Earth materials, including biological samples. The SEM we will purchase is a Philips XL30 ESEM-FEG, which operates with both low- and high-vacuum modes with a field emission gun (FEG) and a software/hardware package for an electron backscattered diffraction (EBSD) pattern analysis. This new facility is critical to the diverse research activities at Yale Geology and Geophysics including studies of: (1) deformation microstructures of experimentally and naturally deformed samples (Karato, Brandon), (2) fluid-rock interaction (Ague, Rye), (3) microbial geochemistry and geomicrobiology (Blake). Complete orientation measurements with high-spatial resolution, as provided by the EBSD package attached to this type of state-of-the-art SEM, are critical to microstructural studies on deformed rocks by Karato and Brandon. Geologic application of this technique is widespread in Europe, but has been limited to only a handful of labs in the United States. The spatial resolution of orientation measurements is close to 0.25 mm when the FEG electron source is used with an EBSD package. Such a high spatial resolution is critical, particularly for the experimental studies in Karato's group where microstructural developments under high-pressure conditions are studied using specimens with very fine grain size. Similarly, the ESEM mode of operation of this SEM has major advantages in several research areas at Yale Geology and Geophysics. This includes the study of fluid-rock interaction through the charge-contrast imaging technique (which works selectively at ESEM mode), and the study of microbial geochemistry and geomicrobiology, which requires high-resolution images of the morphology of mineral surfaces and associated microorganisms. Addition of this facility to the existing analytical and other experimental facilities will significantly enhance the research programs of experimental Earth science at the department of Geology and Geophysics at Yale University.***