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Neutron Residual Stress Mapping Facility (NRSF2) |
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The NRSF2 instrument shutter with preliminary shutter inserts in place (1-in. holes at each end of the 40-in.-long shutter) was first opened in May, and both the beam stop and effectiveness of the shutter inserts were tested for radiological safety. The NRSF2 beam stop was approved for use. Based on the test results, permanent tapered shutter inserts were designed and fabricated. They consist of alternating layers of Fe and borated polyethelene. The new inserts enable a test specimen to view the entire focusing monochromator (~3 × 5 in.) while having a tapered rectangular hole throughout its length to minimize the fast neutron and gamma radiation in the instrument region. The opening at the exit is approximately 0.6 in. wide and 2 in. tall. The double-crystal, doubly focusing monochromator designed and built by Stoica and Popovici (University of Missouri) provides six different crystal planes to deliver six different wavelengths from 1.45 to 2.67 Å. The monochromator was successfully aligned during full-power HFIR operation, and the monochromator settings were as predicted. With the Si331 monochromatic setting, the first diffraction peak at the new instrument was recorded (Fig. 5-2). The sample was a Ni powder in a 5-mm diam capillary tube.
The Neutron Powder Diffractometer is located at the High Flux Isotope Reactor (HFIR) at ORNL and managed by the Neutron Scattering Group, Solid State Division, ORNL. HFIR is supported by DOE-Energy Research. The Neutron Scattering Group is supported by DOE-OS, Division of Materials Sciences. |
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