A Camera for Borrmann Stereo X-Ray Topographs

Abstract

A relatively inexpensive camera which was designed for taking Borrmann topographs with standard X-ray diffraction equipment is described. This camera has been used to take stereo pairs of Borrmann topographs by rotating the crystal around an axis normal to the diffraction planes. Topographs have been taken of nearly perfect copper crystals up to 0.2 cm thick using silver, molybdenum, copper, and chromium radiation, and comparisons have been made with topographs obtained with crystal monochromated radiation. Geometrical factors affecting the resolving power of the technique are briefly reviewed. In addition, the resolution inherent in the diffraction phenomenon is analyzed on the basis of the theory of anomalous transmission. Comparisons are made between calculated and observed image widths of a few dislocations.