How the crystal curvature affects the rocking curve width

In regions of a crystal where the local curvature is large along the direction perpendicular to the rocking axis, a significant part of the rocking curve peak width for a pixel can arise from variation of the peak position within the pixel. The following plots show significant correlation between the observed rocking curve widths and the local curvature for a given row of pixels.

Comparison between rocking curve width (black points, left axis) and local slope of the rocking curve peak angle (blue points, right axis) for a given row of pixels taken during a single scan.

Comparison between rocking curve width (black points, left axis) and local slope of the rocking curve peak angle (blue points, right axis) for a given row of pixels taken during a single scan.