MICRODIFFRACTION DEVELOPMENT

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 过去一年的新发展是将我们的K-B镜系统用于微衍射应用。这种方法允许收集很大一部分可用波束，并为针对特定需求调整波束大小和发散提供了极大的灵活性。功能射束尺寸从大约2×3微米到大约10×10微米不等。这允许从非常小的样品体积收集高质量的衍射，最大限度地减少通过照射样品的非晶态/排列不佳的部分而收集的漫射散射。在确定用于结缔组织应用的高分辨率、低发散度和高通量、大发散度应用的操作参数方面已经取得了相当大的进展，该操作参数可用于研究组织中的淀粉样蛋白沉积等。在样品架前安装了一组新的小孔，以阻止来自KB反射镜系统的有害寄生X射线。这些孔(直径约20微米)安装在由高精度Newport MFN平台驱动的XY定位器上。这些光圈使我们能够通过减少由KB镜引起的一些寄生散射来优化信号与背景的比率。在此期间还测试了一种新的在线样品对齐系统。该系统允许在对准过程中对样品进行可视化，而无需从光束路径移除CCD探测器。这些发展为在即将到来的赠款周期中为BioCAT的前舱设计专门的微衍射装置提供了信息。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. A new development over the last year is the use of our K-B mirror system for micro-diffraction applications. This approach allows collection of a large fraction of the available beam and offers great flexibility in adjusting beamsize and divergence for specific needs. Functional beam size ranges from about 2 x 3 microns to approximately 10x10 microns. This allows collection of high quality diffraction from very small sample volumes minimizing the diffuse scatter collected by irradiating non-crystalline / poorly aligned parts of the sample. Considerable progress has been made in determining the operational parameters for both high resolution, low divergence that are optimal for connective tissue applications and high flux, larger divergence applications which can be useful for studies of such things as amyloid deposits in tissues. A new set of small apertures was implemented in front of the sample holder to block unwanted parasitic x-rays coming from the KB mirrors system. The apertures (~ 20 micron diameter) are mounted on an XY positioner driven by high precision Newport MFN stages. These apertures allowed us to optimize the signal to background ratio by reducing some parasitic scattering originated by the KB mirrors. A new inline sample alignment system was also tested during this period. The system allows the visualization of the sample during the alignment procedure without removing the CCD detector from the beam path. These developments have informed the design of a dedicated micro-diffraction setup for the front of the hutch at BioCAT to be implemented in the upcoming grant cycle.