Neutron Imaging and Tomography in Conservation

Neutron imaging is a radiographic technique that can be conducted in both 2D and 3D (tomography). A neutron beam is directed towards an object; the extent to which the beam is attenuated enables information concerning the object’s internal structure to be gathered. The technique can be useful for conservators, providing a non-destructive, non-invasive means of investigating the composition and structural integrity of an object. Neutron imaging can be used, for instance, to detect structural flaws, soluble salts, metal corrosion, and the degree to which a consolidant has penetrated an object. It forms a useful complement to X-ray radiography: unlike X-rays, which interact with an atom’s electron cloud, neutrons interact with the atom’s nucleus. Materials that are relatively opaque to X-rays, such as dense metals, are often easily penetrated by neutrons, and vice versa. Neutron imaging can, however, cause objects to become radioactive and facilities remain relatively scarce.