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Facilities
The group maintains research programs both in-house and at the Advanced Photon Source, Argonne Il. In addition to these research programs, we are developing neutron-based research for deployment to the HFIR and SNS.
Station 34-ID-E at the APS
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Fig. 3. Microbeam diffraction Laue pattern for dislocation cells in strained Cu (left) and the lattice strain
Dd/do = -Dq/q measured within individual cells (vertical lines) superposed on asymmetric, spatially integrated x-ray line profile (right).
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This facility is the first-of-its-kind instrument for 3D spatially resolved measurements of local crystal structure. The facility includes microfocusing optics to achieve a submicron spot, a special nondispersive monochromator that allows for cycling between monochromatic and polychromatic beams with little beam motion at the sample, special area detectors to collect the Laue patterns from the sample and a differential aperture wire to determine the diffraction distribution along the incident beam. This instrument has the unique ability to nondestructively measure 3D maps of the stress tensor, the Nye tensor, phase distributions and the local orientation matrix with submicron resolution. We receive partner user time for the development of advanced techniques on this experimental station.
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Fig. 8. Cross-section image with two Sn whiskers. Color coding of the Sn indicates grain orientation. Note that the orientations are distinct and that there are grain boundaries in the whiskers. |
Efforts are currently underway to improve the spatial resoluton to <200 nm for the polychromatic microdiffraction facility, and to install a parallel nanobeam facility with a <50 nm beam.
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Fig. 1. Schematic view of the 3D x-ray microscope including white and monochromatic beams focused by K-B mirrors and a diffracted beam profiler to depth analyze beams striking the CCD x-ray detector.
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Laboratory X-ray Instrumentation
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- Three 4-Circle Huber diffractometers with two rotating anode generators
- Displex cooler, furnaces and other sample chambers for diffractometers
- Two powder diffraction instruments with crystal analyzers or solid-state detectors
- Texture instrument
- Laboratory microtomography instrument witn ~1.5 mm spatial resolution
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Neutron capabilities
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Neutron focusing supermirror prototype |
Optics laboratory with long-trace profiler and mirror test bed. Measure mirror figure to less than 10 microradians. Test supermirror focusing geometries.
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