Neutrons for Cultural Heritage-Techniques, Sensors, and Detection.

Advances in research in Cultural Heritage see increasing application of a multidisciplinary approach and the combined use of physical and chemical characterization of artefacts that can be used to define their structure and their state of conservation, also providing valuable information in selecting the most suitable microclimatic conditions for the exhibition environment. This approach provides a platform for a synergic collaboration amongst researchers, restorers, conservators, and archaeologists. Existing state-of-the-art technologies for neutron-based methods are currently being applied to the study of objects of historical and cultural interest in several neutron-beam facilities around the world. Such techniques are non-invasive and non-destructive and are, therefore, ideal to provide structural information about artefacts, such as their composition, presence of alterations due to the environmental conditions, inclusions, structure of the bulk, manufacturing techniques, and elemental composition, which provide an overall fingerprint of the object's characteristics, thanks to the nature of the interaction of neutrons with matter. Here, we present an overview of the main neutron methods for the characterization of materials of interest in Cultural Heritage and we provide a brief introduction to the sensors and detectors that are used in this framework. We conclude with some case studies underlining the impact of these applications in different archaeological and historical contexts.

Aggregation States of Aß1-40, Aß1-42 and Aßp3-42 Amyloid Beta Peptides: A SANS Study.

Aggregation states of amyloid beta peptides for amyloid beta A ß 1 - 40 to A ß 1 - 42 and A ß p 3 - 42 are investigated through small angle neutron scattering (SANS). The knowledge of these small peptides and their aggregation state are of key importance for the comprehension of neurodegenerative diseases (e.g., Alzheimer's disease). The SANS technique allows to study the size and fractal nature of the monomers, oligomers and fibrils of the three different peptides. Results show that all the investigated peptides have monomers with a radius of gyration of the order of 10 Å, while the oligomers and fibrils display differences in size and aggregation ability, with A ß p 3 - 42 showing larger oligomers. These properties are strictly related to the toxicity of the corresponding amyloid peptide and indeed to the development of the associated disease.

Optimization of detection strategies for epithermal neutron spectroscopy using photon-sensitive detectors.

In this work, we discuss an improved detection procedure for the photon-sensitive yttrium-aluminum-perovskite detectors installed on the VESUVIO spectrometer at the ISIS pulsed neutron and muon source. By decreasing the low-level energy threshold of detected photons, we observe an increased count rate up to a factor ∼3, and a decrease of relative error bars and noise of ∼40% and 35%, respectively, for deep inelastic neutron scattering measurements. In addition, we demonstrate how the reported optimization may increase the accuracy in the line shape analysis of neutron Compton profiles, as well as in the application of the mean-force approach to detect the anisotropy and anharmonicity in the single-particle local potential. We envisage that such an upgrade of the detection procedure would have a substantial impact on the VESUVIO scientific programme based on deep inelastic neutron scattering investigations.

Egyptian Grave Goods of Kha and Merit Studied by Neutron and Gamma Techniques.

Artifacts from the Egyptian grave goods of Kha and Merit preserved at the Museo Egizio in Turin were studied through a combination of non-destructive and non-invasive neutron and gamma techniques (namely neutron imaging, neutron diffraction and prompt gamma activation analysis). The results provide unprecedented morphological reconstructions of the inner parts of the two alabaster and metallic vases and their isotopic and phase composition, thereby extending our knowledge of the hitherto unknown content of the vases and their functions.