Browsing by Author "Foran, G"

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    The Australian National Beamline Facility at the Photon Factory
    (American Institute of Physics, 1994) Garrett, RF; Cookson, DJ; Foran, G; Creagh, DC; Wilkins, SW
    The Australian National Beamline Facility has been installed at the Photon Factory, Tsukuba, Japan. The construction and operation of the facility has been funded by a consortium of Australian research organizations, universities, and government funding agencies, with the aim of providing Australian scientists with routine access to synchrotron radiation in the hard‐x‐ray region. The first experiments were performed at the ANBF in November 1992. The facility consists of a general purpose x‐ray‐beamline, including a simple two‐crystal monochromator, delivering either monochromatic x rays (range 5–20 keV) or white radiation to the experimental hutch. The main experimental instrument, a multiconfiguration diffractometer, has recently been installed at the beamline. This unique instrument combines vacuum operation and imaging plate detectors, and can be configured for high‐resolution powder diffraction (including a time resolved mode), protein crystallography, and triple‐axis experiments. In addition, the white or monochromatic beam can pass through the diffractometer to a secondary experimental table, where experiments such as EXAFS, Laue diffraction, topography, and microbeam measurements are performed. Details of the beamline, monochromator, and diffractometer optics and performance will be described, and an overview will be given of the experimental capabilities of the facility. © 1995 American Institute of Physics.
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    High‐resolution triple‐crystal x‐ray‐diffraction experiments performed at the Australian National Beamline Facility in Japan
    (American Institute of Physics, 1994-07-18) Nikulin, AY; Stevenson, AW; Hashizume, H; Wilkins. SW; Cookson, DJ; Foran, G; Garrett, RF
    The x‐ray‐diffraction results reported here are from the first high‐resolution triple‐crystal experiments to be performed at the Australian National Beamline Facility at the Photon Factory. The heart of the facility is a multipurpose two‐axis high‐resolution vacuum diffractometer (BIGDIFF) Z. Barnea et al., Rev. Sci. Instrum. 63, 1069 (1992) capable of use for high‐resolution powder diffraction (using both conventional scintillation detectors and imaging plates), protein crystallography, reflectometry, as well as single‐crystal diffractometry. The present experiments were conducted on BIGDIFF in triple‐crystal diffraction mode with a monolithic channel‐cut Si monochromator (supplied by Professor M. Hart), a single‐crystal Si sample, and a four‐reflection monolithic channel‐cut Si analyzer crystal. The Si(111) sample is a part of a wafer which had been implanted with 100 keV B+ ions (doses 1×1015 and 5×1015 cm−2) through a one‐dimensional 0.5 μm thick oxide strip pattern with a 5.83 μm period and 4 μm open region. The triple‐crystal data were collected in the form of two‐dimensional intensity maps in the vicinity of the 111 Bragg peak, varying the sample rotation (ω) and the analyzer/scintillation detector rotation (2θ). The first results were collected in air both with the as‐described sample and after the oxide layer had been removed. Certain slice scans (one‐dimensional sections of the two‐dimensional intensity maps) were also collected with a vacuum of 1 Torr and reveal considerable improvement in signal to background. The data will be compared with a recent similar study A. Yu. Nikulin et al., J. Appl. Cryst. 27, 338 (1994) performed on BL‐14B at the Photon Factory. The new data collected in air indicate that lattice distortion may be mapped with a resolution of approximately 160 Å, to a depth of approximately 1.0 μm, providing valuable quantitative information on ion diffusion in such implanted materials. The slice scans collected in vacuum indicate that a depth resolution of 50 Å is certainly achievable using BIGDIFF. The data show the excellent potential of BIGDIFF for extremely good signal to noise and very high resolution in such experiments, and the advantages of working entirely in vacuum. © 1995 American Institute of Physics.