J. Synchrotron Rad. (1997). 4, 95-101 [ doi:10.1107/S090904959601432X ]
Abstract: Advantage was taken of the highly focused X-ray beam (10-30 ![[mu]](/logos/entities/mu_rmgif.gif)
m) and the broad white spectrum of synchrotron X-rays at the ESRF for automatic recording of Laue patterns from polycrystals and extraction of orientation information. The procedure used is similar to that applied for electron-backscattering patterns in the scanning electron microscope and provides data for local orientation mapping used in texture analysis. Laue patterns are obtained from a thin slice of material in transmission and recorded with a CCD detector. The Laue geometry is converted into a gnomonic projection in which co-zonal reflections lie on straight lines. On applying the Hough transform these lines are merged into a single point, which is recognized by the computer and assigned zone indices [uvw] by comparison with a table of interzonal angles. From the angular positions of several [uvw] the crystal orientation is calculated. The method is illustrated for the orthorhombic magnesium silicate olivine.
Keywords: Laue patterns; texture analysis; indexing (automatic); orientation determination; olivine; gnomonic projection.
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