Neutron Imaging: A Non-Destructive Tool for Materials Testing

Description

IAEA, Report of a coordinated research project 2003–2006, Vienna, 2008Neutron radiography is a powerful tool for non-destructive testing of materials for industrialapplications and research. The neutron beams from research reactors and spallation neutronsources have been extensively and successfully used for neutron radiography over the last fewdecades. The special features of neutron interaction with matter make it possible to inspectbulk of specimen and to produce images of components containing light elements such ashydrogen beneath a matrix of metallic elements, like lead or bismuth. The technique iscomplementary to X ray and gamma ray radiography and finds applications in diverse areassuch as the examination of nuclear fuels and the detection of explosives.The neutron source properties, the collimator design and the fast and efficient detectionsystem decide the performance of a neutron radiography facility. Research and developmentin these areas becomes essential for improving the output. Detection systems have taken a bigjump from conventional photographic film to digital real-time imaging. The use of fast andepithermal neutrons as sources and the exploitation of more specialized neutron interactions,like resonance absorption and phase shifts, has further opened up the field of neutron imagingfor research and development. Application of new types of radiation detectors and improvedsignal processing techniques with an increase in the efficiency and resolution will bebeneficial for low intensity neutron sources.Although neutron radiography is used in many research reactor centres, only a few are welldeveloped and have state-of-the-art facilities, while the remainder still continue to use lowend technology such as the film based detection system.