DESCRIPTION OF MULTIPLE-CRYSTAL DIFFRACTION INCLUDING ASYMMETRIC REFLECTIONS

The diffraction on Bragg-case multiple-crystal arrangements is treated for arbitrary configurations, numbers, and angular positions of crystals including asymmetric reflections on all crystals. In order to consider the influence of reflection asymmetry, the quantities which describe the diffraction process geometrically, are to be modified. The modification can be related to any certain partial beam path in the arrangement. Expressions for the reflectivity of general multiple-crystal arrangements are obtained using the modified quantities in the arguments of the reflection functions. For various three-crystal arrangements with asymmetric reflections, reflectivity ratios and halfwidths of simulated and measured rocking curves are compared.