MICRODIFFRACTION DEVELOPMENT

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 在过去的一年里，我们的一个新的发展是将我们的K-B镜系统用于微衍射应用。这种方法允许收集大部分可用光束，并提供了很大的灵活性，在调整光束大小和发散度的特定需求。功能光束尺寸范围从约2 × 3微米到约10 × 10微米。这允许从非常小的样品体积收集高质量的衍射，从而最小化通过照射样品的非结晶/不良对准部分收集的漫散射。在确定对于结缔组织应用最佳的高分辨率、低发散度和对于组织中淀粉样蛋白沉积物的研究有用的高通量、较大发散度应用的操作参数方面已经取得了相当大的进展。 在样品保持器前面安装了一组新的小孔，以阻挡来自KB镜系统的不必要的寄生X射线。孔径（~ 20微米直径）安装在由高精度纽波特MFN载物台驱动的XY定位器上。这些孔径使我们能够通过减少KB反射镜产生的一些寄生散射来优化信号与背景比。 在此期间还测试了一种新的在线样品校准系统。该系统允许在校准过程中对样品进行可视化，而无需将CCD检测器从光路中移除。这些发展为BioCAT的专用微衍射装置的设计提供了信息，该装置将在即将到来的资助周期中实施。

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.