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![[Figure 9]](vb5096fig9mag.jpg)
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Figure 9
Calibration accuracy. Relative peak-position error for the 100, 110, 111 and 200 reflections with (A) the conventional transmission detector geometry and (B), (C) the detector tilted relative to the incoming beam. Diffractograms were integrated over a 5° sector of the azimuthal angle to assess precision and accuracy as a function of the projection angle across the detector panel. Diffraction measurements are repeated by applying a displacement in the gravity direction, i.e. tomography-stage y axes, to the capillary sample [first rows of (A) and (B)] and to a flat-plate sample in the normal-to-the-beam direction [second rows of (A) and (B), and all of (C)], i.e. tomography-stage combined x and z axes. In (C) the measurements are repeated for the same relative displacements of the center of scattering by moving the diffraction beam while the sample stays stationary. For this, the relative error is computed either using self-calibrated geometry [first row of (C)] or by extrapolating the geometry correction for the beam shift alone [second row of (C)] or the combined beam shift and relative detector tilt [third row of (C)]. A relative peak-position error of 0.05% corresponds to a relative interplanar-distance error of ~0.0065% for a 1.8953 Å d0 observed with a 25 keV X-ray beam. |
![[Figure 9]](vb5096fig9.jpg)
 | JOURNAL OF APPLIED CRYSTALLOGRAPHY |
ISSN: 1600-5767
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