Neutron radiography is a radiographic technique based on the use of neutrons (instead of classical X-rays).It has a minor role in the cultural heritage area, but it could be a complementary technique if one wants for instance, to look for organic materials inside a closed metal object. The difference between neutron and X-ray interaction mechanisms produce significantly different and sometimes complementary information. While X-ray attenuation is directly dependent on atomic number, neutrons are efficiently attenuated by only a few specific elements like hydrogen, boron, rare earths, cobalt, lithium, indium, mercury, gold, silver…. For example, organic materials or water are clearly visible in neutron radiographs because of their high hydrogen content, while many structural materials such as aluminium, steel or lead are nearly transparent. The examination must be done in a thermal neutron beam extracted from a research nuclear reactor, like the one dedicated to this technique at the Orphée reactor at CEA – Saclay.
- H. Berger, Neutron radiography. Methods, capabilities and applications, Elsevier, Amsterdam (1965)
- G. Bayon, Les contrôles non destructifs et la neutronographie, Proc. 7ème Conf. Européenne sur les CND, Nice 1043 (1994)