How the crystal curvature affects the rocking curve width
From GlueXWiki
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 differences between the rocking curve widths observed in the (-2 2 0) and (2 2 0) orientations that may be attributed to the differences in the local curvature along the two axes.