Stefan Hartmann

Quantitative characterization of Japanese ancient swords through energy-resolved neutron imaging

Japanese blades are culturally interesting objects both from the stylistic point of view and because of their fantastic performance. In this work, we present new results, using a non-invasive approach, concerning these peculiar artefacts. Five Japanese swords pertaining to Koto (987–1596) and Shinto (1596–1781) periods have been analysed through white beam and energy resolved neutron-imaging techniques. The experiments have been performed at the ICON beam line, operating at the spallation neutron source SINQ, Paul Scherrer Institut in Switzerland. The reconstruction of projection data into neutron tomographic slices or volumes allowed us to identify some peculiar characteristics, related to the forging methods that were used by the different schools and traditions in Japan.

Quantitative neutron imaging of water distribution, venation network and sap flow in leaves

AbstractMain conclusionQuantitative neutron imaging is a promising technique to investigate leaf water flow and transpiration in real time and has perspectives towards studies of plant response to environmental conditions and plant water stress. The leaf hydraulic architecture is a key determinant of plant sap transport and plant–atmosphere exchange processes. Non-destructive imaging with neutrons shows large potential for unveiling the complex internal features of the venation network and the transport therein. However, it was only used for two-dimensional imaging without addressing flow dynamics and was still unsuccessful in accurate quantification of the amount of water. Quantitative neutron imaging was used to investigate, for the first time, the water distribution in veins and lamina, the three-dimensional venation architecture and sap flow dynamics in leaves. The latter was visualised using D2O as a contrast liquid. A high dynamic resolution was obtained by using cold neutrons and imaging relied on radiography (2D) as well as tomography (3D). The principle of the technique was shown for detached leaves, but can be applied to in vivo leaves as well. The venation network architecture and the water distribution in the veins and lamina unveiled clear differences between plant species. The leaf water content could be successfully quantified, though still included the contribution of the leaf dry matter. The flow measurements exposed the hierarchical structure of the water transport pathways, and an accurate quantification of the absolute amount of water uptake in the leaf was possible. Particular advantages of neutron imaging, as compared to X-ray imaging, were identified. Quantitative neutron imaging is a promising technique to investigate leaf water flow and transpiration in real time and has perspectives towards studies of plant response to environmental conditions and plant water stress.

Non-invasive characterization through X-ray fluorescence and neutron radiography of an ancient Japanese lacquer

Oriental lacquer artefacts represent very interesting objects of investigation, involving a huge variety of materials and manufacturing techniques. Lacquers are very attractive not only for their stylistic features but also for understanding the variety of production processes, time evolution, use and artistic applications involved in their manufacturing. Till recently, the research activity on these materials has been mainly based on standard, more or less invasive, analytical methods. With the aim to characterise a nineteenth century Japanese lacquer in a totally non-invasive and non-destructive way, in situ X-ray fluorescence (XRF) and neutron radiography (NR) have been employed. While XRF suggested an identification of the pigments embedded into superficial layers, NR allowed revealing, in a single measurement, the average bulk properties of the sample.

Combined neutron and synchrotron X-ray microprobe analysis: attempt to disclose 3600 years-old secrets of a unique bronze age metal artifact

Over the most recent years, micro-analytical facilities based on neutron beams as well as synchrotron X-ray radiation advanced to indispensable instruments in the context of investigating artwork and archaeological artifacts. Using a combined approach of neutron and X-ray micro-beam techniques we investigated a uniquely decorated flanged axe dated into the Early Bronze Age (2200–1600 BC). This axe found in Central Europe is in view of its very early dating and striking parallels to Greek objects one of the most important artifacts concerning the provenance of its particular decoration technique. Neutron tomography was employed to obtain a full three-dimensional structural analysis of the object. Complementary, X-ray microprobe investigations were used to produce two-dimensional chemical and crystallographic images with high spatial resolution. The analysis of the internal structural details of the historical object provides invaluable information regarding manufacturing techniques and material properties. Important insights were obtained for different steps of the object creation including the body casting, the smithing, and—most important—the unique damascening decoration. The compositional analysis and the chemical imaging yield crucial information about the provenance of the metallic raw materials used. The technical and structural peculiarities observed for the axe of Thun-Renzenbuhl reveal distinct differences as compared to Mediterranean objects. Additionally, the chemical analysis of the copper inlays used as part of the decoration point towards the usage of pure copper metal, again in contrast to the more ‘exotic’ copper–gold alloys employed in the Mediterranean damascening decorations. Contradictory to the widely accepted conception of a strong influence of Mediterranean cultures, the present findings point towards a considerable influence of Bronze Age Central Europe by cultures located in the Balkan Peninsula and Caucasus region.

Creating a reference database of cargo inspection X-ray images using high energy CT of cargo mock-ups

Customs continue to use a wide range of technology in protecting against terrorism and the movement of illicit trade and prohibited imports. The throughput of scanned vehicles and cargo increases and just keeps on growing. Therefore, the need of automated algorithms to help screening officers in inspection, examination or surveillance of vehicles and containers is crucial. In this context, the successful collaboration between manufacturers and customs offices is of key importance. Facing this topic, within the seventh framework program of the European Commission, the project ACXIS “Automated Comparison of X-ray Images for cargo Scanning” arose. The main objective of this project is to develop a manufacturer independent reference database for X-ray images of illicit and licit cargo. Historic images of real detections, images of illegal cargo mock-ups as well as images of legitimate cargo will be integrated into the reference database. For this, procedures and algorithms to uniform X-ray images of different cargo scanners was developed, as well as an automated identification method of potentially illicit cargo. Finally, these developments were incorporated in creating a training simulator and a toolbox for inspection officers enhanced X-ray screening competence.