Non-destructive characterization of archaeological glasses by neutron tomography

The present work is carried out in the framework of a National Italian Project, whose aim is the assessment of innovative physical non-destructive techniques applied to archaeology. Towards this end, some archaeological artefacts have been studied by our group, in collaboration with the National Museum of Altino (VE) and EniTecnologie S.p.A. The objects come from the excavations in Altino, near Venice, where at least three different historical layers are present, corresponding to ages starting from approximately VII century B.C. In particular, in this work the results of neutron tomography investigations on three I-II century A.D. glass fragments are reported. The experiments were performed at the cold neutron radiography facility CONRAD at HMI (Berlin). For the 3D tomographical reconstruction of the sample, 200 projections were collected while the sample was rotated around a defined axis. The rotation interval was 180 degrees. The results show that the technique is able to reconstruct well the structural features of the investigated objects such as, in particular, highly absorbing zones and the presence of defects in the bulk