(1Delft-University of Technology, Delft, the Netherlands / 2EC-JRC-IRMM, Geel, Belgium / 3National Museum of Antiquities (RMO), Leiden, the Netherlands)

Outline: non-destructive analytical method for precious cultural heritage objects

Neutron resonance capture analysis (NRCA) is based on peaks occurring in the absorption spectrum of neutrons as a function of their energy. These so-called “resonance” peaks are specific for each element/isotope and therefore suitable to recognize and to quantify elements in objects. Neutrons can penetrate thick layers of materials, and therefore this method provides bulk compositions. The energies of captured neutrons can be readily determined with the time-of-flight method using a pulsed source of neutrons. NRCA is the latest member of neutron-based methods for analyzing objects and materials. It is developed in the EC-JRC-IRMM research centre in Geel (B) using the pulsed source of neutrons and time-of-flight systems of its GELINA facility. NRCA is a fully non-destructive method; it is not necessary to take samples. The activation is low directly after the measurement and negligible after a short waiting period. NRCA has been applied in the study of ancient bronze objects. Recently two objects, on loan from the National Museum of Antiquities in Leiden (NL) have been analyzed, the Buggenum sword, and the Jutphaas dagger. Both objects are in excellent condition and have likely been served as ceremonial objects in the Mid to Late Bronze Age period in Europe. They have been found at locations in the Netherlands far from their probable production areas. For the study of their compositions it was not allowed to use analytical methods, which need samples to be taken from objects. For this reason they were studied by NRCA at the GELINA facility. This research is part of the European Ancient Charm project.

Keywords: Neutrons, analytical method, bronze-age objects