MICRO WIDE ANGLE FIBER DIFFRACTION DEVELOPMENT AND CHARACTERIZATION

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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. One of the core projects in the current grant cycle is the development of a flexible, high flux instrument for micro-diffraction of small ordered domains in biological materials with emphasis on studies of connective and neurological tissue. The micro-diffraction capabilities should meet the following requirements: For wide angle: d-space range 200-3.0 ¿ to resolve amyloid cross-beta signatures and higher harmonics of any features from super-helices. For small angle a d-space range of 800-100 ¿ to resolve first order of collagen (670) with overlap with WAX data for merging of low and high angle data and resolution of Tau fiber helical twist (~800 ¿). The focal spot sizes, on the sample, need to be less than 10 microns (preferably much less) in each direction. Use of cryo-crystallography equipment will be extremely important for the micro-diffraction modes, to prevent radiation damage in the sample while exposed to the X-ray beam over extended periods of time.