Figure 4.4.2.1 

Two methods by which artificial mosaic monochromators can be constructed: (a) out of a stack of crystalline wafers, each with a mosaicity close to the global value. The increase in divergence due to the mosaicity is the same in the horizontal (left picture) and the vertical (right picture) directions; (b) out of several stacked thin crystalline wafers each with a rather narrow mosaic but slightly misoriented in a perfectly controlled way. This allows the shape of the reflectivity curve to be rectangular, Gaussian, Lorentzian, etc., and highly anisotropic, i.e. vertically narrow (right picture) and horizontally broad (left figure).