Acquisition of a Four-Circle Single-Crystal Diffractometer with CCD Detector

9725354 Finger这笔拨款部分支持购置一台带有CCD探测器的新型四圆单晶x射线衍射仪的费用。该区域探测器的灵敏度比以前的模型高得多，并且可以收集衍射强度的二维截面，这些截面可以组合起来构建一个完整的倒易空间三维视图。有了这些信息，就有可能研究非常小的晶体或孪生晶体，并研究由各种无序源引起的漫射散射。地球物理实验室的x射线小组由Larry Finger， Charles Prewitt， Robert Hazen和贺雄Yang组成，他们将开发必要的技术，将CCD探测器系统与钻石砧细胞结合使用。有了新的仪器，它将有可能在更短的时间内测量晶格常数并进行晶体结构细化，而不是目前用于晶格常数测定的时间。高压晶体学是了解地球深部相关系的重要组成部分。一旦该仪器安装完毕，25%的工作时间将作为区域资源，重点放在地球科学界。它还将被用作实验室暑期实习计划的资源，该计划由REU拨款资助。＊＊＊

9725354 Finger This grant provides partial support of the costs of acquiring a new four-circle single-crystal X-ray diffractometer with a CCD detector. This area detector has much higher sensitivity than previous models, and collects two-dimensional sections of the diffracted intensity that can be combined to construct a full three-dimensional view of reciprocal space. With such information, it is possible to study very small or twinned crystals, and to study diffuse scattering arising from various sources of disorder. The X-ray group at the Geophysical Laboratory, consisting of Larry Finger, Charles Prewitt, Robert Hazen, and Hexiong Yang, will develop the necessary techniques to use the CCD detector system with the diamond-anvil cell. With the new instrument, it will be possible to measure lattice constants and perform a crystal- structure refinement in less time than currently used for a lattice-constant determination. High-pressure crystallography is an essential component in understanding phase relations in the deep earth. Once this instrument is installed, 25% of the operating time will be available as a regional resource, with emphasis on the earth science community. It will also be used as a resource in the Laboratory's summer intern program, which is funded a by a REU grant. ***