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Article: NCNR PUTS INTO OPERATION NEW PERFECT CRYSTAL DIFFRACTOMETER FOR ULTRA-HIGH RESOLUTION SANS.(Brief Article)
- Article from:
- Journal of Research of the National Institute of Standards and Technology
- Article date:
- September 1, 2000
CopyrightCOPYRIGHT 2000 National Institute of Standards and Technology. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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A perfect crystal diffractometer (PCD) for ultra-high resolution small-angle neutron scattering (USANS) measurements is now operational at NIST's Center for Neutron Research (NCNR). The PCD increases the maximum size of features accessible with the NCNR's 30 m long, pinhole collimation SANS instruments by nearly two orders of magnitude, from [approximate][10.sup.2] nm to [10.sup.4] nm.
The PCD is a Bonse-Hart-type instrument with large triple-bounce, channel-cut silicon (220) crystals as monochromator and analyzer. The perfect crystals provide high angular resolution while the multiple reflections suppress the "wings" of the beam profile, improving the ...