Using neutron imaging methods for the non-destructive investigation of large ancient bronze artefacts

Abstract

We report about the method of neutron imaging which can be considered as complement and alternative to the more common X-ray techniques. While the image quality obtained (resolution, dynamic, contrast) is comparable, the particular sensitivity for the investigated materials can differ much. With respect to bronze objects containing Cu, Sn, Zn or Pb in large amounts, the transmission of neutrons is considerably higher than is possible with common X-ray devices. Furthermore, traces of organic materials (corrosion products, resin, wax, oil, lacquer) can be detected accurately. The report describes by means of selected examples how to apply the neutron techniques most efficiently and what infor- mation can be derived from these studies. In addition we describe in brief some alternative analytical tools based on X-ray fluorescence and diffraction that are applicable for material characterization on the surface. The beam lines at PSI’s large-scale facilities can be used on demand if the scientific justification for a dedicated study is submitted in a proposal. (Key words: neutron imaging, bronze objects, tomography, complementarity, X-rays)