Neutron resonance spectroscopy for the characterization of materials and objects

Abstract

The resonance structure in neutron induced reaction cross sections can be used to determine the elemental compositions of materials or objects. The occurrence of resonances is the basis of neutron resonance capture analysis (NRCA) and neutron resonance transmission analysis (NRTA). NRCA and NRTA are fully non-destructive methods to determine the bulk elemental composition without the need of any sample preparation and resulting in a negligible residual activity. They have been applied to determine the elemental composition of archaeological objects and to characterize reference materials used for cross section measurements. For imaging applications a position sensitive neutron detector has been developed within the ANCIENT CHARM project. The detector is based on a 10 × 10 array of ⁶Li-glass scintillators mounted on a pitch of 2.5 mm, resulting in a 25 × 25 mm² active area. The detector has been tested at the time-of-flight facility GELINA and used at the ISIS spallation source to study cultural heritage objects.