Three-dimensional X-ray microscopy with accurate registration of tomographic sections.

X-ray microtomography has been used to study the internal flaws and external shape of a 0.75 X 1 mm copper sulphate crystal at a resolution of 25 microns. The problems of accurate tomographic reconstruction and the subsequent registration of the reconstructed sections to give a complete 3-D image are considered when the position of the axis of rotation of the specimen varies slightly between projections.