A kinematic diffraction simulation model was developed in order to improve the understanding of direct dislocation images in synchrotron white-beam X-ray topographs, and was successfully used to illustrate the contrast-generating mechanisms which were involved in images of micropipe-related super-screw dislocations. An agreement of the simulations with the contrast features of super-screw dislocation images, as recorded using a series of synchrotron topography techniques, showed that the present model was capable of revealing the detailed diffracting behavior of the highly distorted regions around the dislocation core. The simulation technique was demonstrated to be a simple but efficient method for interpreting synchrotron topographs, and could be used to explain the topographic contrast characteristics of general crystal defects.

Super-Screw Dislocation Contrast in Synchrotron White-Beam Topographs - an Accurate Description of the Direct Dislocation Image. X.R.Huang, M.Dudley, W.M.Vetter, W.Huang, W.Si, C.H.Carter: Journal of Applied Crystallography, 1999, 32[3], 516-24