This proposal seeks funding to purchase a new X-ray diffraction (XRD) instrument. The current 20 year old instrument has developed electrical problems and suffers from unreliable background stability. The manufacturer of the current instrument has since gone out of business and no support options are available. The requested upgrade will be capable of general powder X-ray diffraction, micro-diffraction, and wide angle X-ray scattering. Also proposed is a 2-D image plate detector system. XRD is a common technique for studying Earth and extraterrestrial materials. The research team will put the requested instrument into service to 1) better understand mineralogical signals indicative of supporting life found in Earth and planetary samples, 2) better understand rock-water interactions through mineral signatures, 3) determine biosignatures in Earth and planetary rocks, 4) understand the role of microbes in mediating redox reactions in Fe-bearing clays and Fe-oxides in addition to U(IV) mineral formation and redox processes in the subsurface, and 5) quantitatively survey clay, carbonate and feldspar/quartz mineralology in glacial tills, eolian sediments, and lacustrine deposits in order to reconstruct paleoclimatic changes. The new instrument will be housed in current X-ray Diffraction Laboratory at UWM. Current infrastructure (cooling water, AC, power, distilled water, etc) is in place to support the acquisition. A 50%-time XRD lab manager will support operation and is supervised by the PI. The lab manager will train new users, provide tech support, maintain the XRD and associated instruments, develop techniques and keep general records. A first-come, first-serve web-based sign up system is in place for the current instrument and will continue to be used. Users pay an hourly fee. The fees support 25% of the FTE lab manager and maintenance costs. The old instrument will be kept for training purposes.
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