Browsing by Author "Fleenor, M"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    The CG1 instrument development test station at the high flux isotope reactor
    (Elsevier, 2011-04-01) Crow, L; Robertson, L; Bilheux, H; Fleenor, M; Iverson, E; Tong, X; Stoica, D; Lee, WT
    The CG1 instrument development station at the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory began commissioning operation in 2009. When completed, the station will have four beams. CG1A is a 4.22 angstrom monochromatic beam intended for spin-echo resolved grazing incidence scattering (SERGIS) prototype development. Initial beam operation and characterization are in progress. CG1B will be a 2.35 angstrom monochromatic beam for a 2-axis utility diffractometer for sample alignment and monochromator development. CG1C will have a double-bounce monochromator system, which will produce a variable wavelength beam from about 1.8-6.4 angstrom, and will be used for imaging and optical development. The CG1D beam is a single chopper time-of-flight system, used for instrument prototype and component testing. The cold neutron spectrum, with an integrated flux of about 2.7 x 10(9) n/cm(2) s, has a guide cutoff at 0.8 angstrom and useful wavelengths greater than 20 angstrom. Initial results from CG1 include spectral characterization, imaging tests, detector trials, and polarizer tests. An overview of recent tests will be presented, and upcoming instrument prototype efforts will be described. (C) 2010 Elsevier B.V. All rights reserved.
  • No Thumbnail Available
    Item
    In-situ polarized 3 He-based neutron polarization analyzer for SNS magnetism reflectometer
    (Insitute of Physics, 2010-12-16) Lee, WT; Tong, X; Pierce, J; Fleenor, M; Ismaili, A; Robertson, JL; Chen, WC; Gentile, TR; Hailemariam, A; Goyette, R; Parizzi, A; Lauter, V; Klose, F; Kaiser, H; Lavelle, C; Baxter, DV; Jones, GL; Wexler, J; McCollum, L
    We report here the construction and neutron transmission test results of an in-situ polarized 3 He-based neutron polarization analyzer system for the Magnetism Reflectometer at the Spallation Neutron Source, Oak Ridge National Laboratory. The analyzer uses the Spin-Exchange Optical Pumping method to polarize the 3 He nuclei of a cell of 3 He gas. Polarized neutrons scattered from the sample are intercepted by the polarized 3 He gas which strongly absorbs neutrons in one spin-state while allowing most neutrons in the other spin-state to pass through. To maintain a stable analyzing efficiency during an experiment, the 3 He gas is continuously polarized in - situ on the instrument. Neutron transmission measurements showed that 73% 3 He polarization was reached in this setup. © 2010, Insitute of Physics.