Gamma ray scattering non-destructive examination

A small scale research instrument based on the Compton scattering of 59.54 keV gamma radiation has been developed to investigate the sensitivity of the technique for the characterization of defects incorporated in copper and stainless steel (SS) phantoms. The basic components of the scanner consist of a radioisotope source enclosed in a labyrinth of lead containing a small cylindrical aperture defining the primary beam and a collimated high-purity germanium detector. Voids with fractional volumes of 16% or more of the intersection volume element (voxel) can be detected and characterized when embedded at different depth levels of the bulk material. (author)