X- and γ-ray tomography in NDE applications

The basic principles of transmission tomography using X- and γ-radiations are briefly reviewed, for industrial applications, gamma sources have many advantages over X-ray tubes, but can never rival them in intensity. Therefore with γ-ray sources it is particularly important to make optimum use of their photon flux and various ways of doing this are considered. Finally a range of NDE applications are outlined to show the potential of these methods.