Neutrons for Cultural Heritage—Techniques, Sensors, and Detection

Abstract

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.

The impact of moderate heating on human bones: an infrared and neutron spectroscopy study

“…The material and methods employed are similar to those used previously [ 18 , 21 , 22 , 24 , 26 , 28 , 35 , 39 ], so only a summary is provided here. More detailed information on the materials, sample preparation, FTIR-ATR acquisition, and INS fundamentals, acquisition and analysis can be found in the electronic supplementary material.…”

“…In addition to having no selection rules, it allows access to the very low energy range of the spectrum (0–400 cm −1 ) with high sensitivity, thus enabling the detection of vibrational features arising from bone's inorganic framework [ 18 , 24 , 28 ]. A few initial reports on the application of INS to the analysis of unburned faunal bone [ 36 – 38 ] were later extended by the authors to human burned skeletal remains [ 18 , 21 , 22 , 24 , 26 , 28 , 35 , 39 ]. (A more extensive description of INS is given in the electronic supplementary material.)…”

“…Fourier transform infrared (FTIR) spectroscopy has been shown to be a technique of choice for the study of bone tissue, even upon extensive burning, since it allows a molecular level analysis with high accuracy and sensitivity, providing reliable information on the heat-induced chemical and structural alterations [15,[18][19][20]24,[28][29][30][31]. In particular, FTIR in attenuated total reflectance (ATR) mode, avoiding any type of sample preparation and requiring minimal amounts of bone, has become the most commonly used, rapid and non-invasive, spectroscopic tool for the analysis of skeletal remains, both recent [23,24,28,32] and archaeological [17,21,26,[33][34][35]. Inelastic neutron scattering (INS) is a nonoptical vibrational spectroscopy technique very suitable for probing bone since it is highly sensitive to royalsocietypublishing.org/journal/rsos R. Soc.…”

Profiling of human burned bones: oxidising versus reducing conditions

“…samples subject to temperatures below 600-700 °C. FTIR, often using the attenuated total reflectance (ATR) mode (which avoids any type of sample preparation), has become the most commonly applied non-invasive vibrational spectroscopy tool for analysing skeletal remains, both in forensic 5,22,26 and archaeological 23,24,[27][28][29][30] sciences. INS, in turn, is an extremely useful technique for probing a hydrogenous material such as bone, the intensity of each vibrational transition being expressed, for a given atom, by the dynamic structure factor where Q(Å −1 ) is the momentum transferred to the sample, ν k is the energy of a vibrational mode, u i (Å ) is the displacement vector of atom i in mode k, σ is the neutron scattering cross section of the atom, and α i (Å) is related to a mass-weighted sum of the displacements of the atom in all vibrational modes.…”

Innovative Technologies for Cultural Heritage. Tattoo Sensors and AI: The New Life of Cultural Assets

“…Furthermore, the great opportunity to assemble hyphenated techniques [4], as NMR-MOUSE [5], neutrons [6] physical approaches represents a future challenge in cultural heritage restoration and conservation/valorization management. Only this multi-disciplinary approach could achieve impact and success for a global characterization of artwork objects and valorization of archaeological surfaces, providing very useful information to restorers and conservator scientists when they approach in terms of experimental restoration and conservation treatments.…”