Developments in computer simulation of X-ray diffraction contrast images of stacking faults

Computer-simulated X-ray section topograph images of a specimen containing a single large-area stacking fault are compared with the experimental image to illustrate useful improvements in simulation realism with regard to both image geometry and stacking-fault fringe contrast. The computer-program developments include exact treatment of the X-ray polarization factor so that anomalous transmission and the periodic fadings of fringe visibility occurring when unpolarized or partially polarized sources are used can be correctly computed. A procedure is described for photographing a cathode-ray-tube display to obtain records with acceptable resolution, contrast and freedom from distortion.