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International
Tables for Crystallography Volume C Mathematical, physical and chemical tables Edited by E. Prince © International Union of Crystallography 2006 |
International Tables for Crystallography (2006). Vol. C. ch. 4.4, p. 434
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![[Figure 4.4.2.2]](/figures/Cbfig4o4o2o2.gif)
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Figure 4.4.2.2
Reciprocal-lattice representation of the effect of a monochromator with reciprocal-lattice vector τ on the reciprocal-space element of a beam with divergence α. (a) For an ideal crystal with a lattice constant width Δτ; (b) for a mosaic crystal with mosaicity η, showing that a beam with small divergence, α, is transformed into a broad exit beam with divergence 2η + α; (c) for a gradient crystal with interplanar lattice spacing changing over Δτ, showing that the divergence is not changed in this case. |