MLZ Conference: Neutrons for Culture and Art

19 Jun 2018, 11:00 → 22 Jun 2018, 12:00 Europe/Berlin

Arabella Brauneck Hotel

The MLZ Conference Neutrons for Culture and Art addresses archaeologists and conservators from museums and universities and aims to illustrate the potential of neutron methods in cultural heritage research. Talks and posters will be presented by renowned international researchers, physicists, and archaeologists in the field to demonstrate state-of-the-art methods and applications.

Poster

Tuesday 19 June

11:00 Registration

12:15 Lunch

Welcome: by Prof. Dr. Peter Müller-Buschbaum (Scientific Director FRM II, Scientific Director MLZ)

Non-destructive characterisation by Scattering and Diffraction Methods

1 THE ANCIENT STEEL TECHNOLOGY IN THE FAR-EAST REVEALED THROUGH NEUTRON IMAGING AND NEUTRON DIFFRACTION

The metallurgy of historic weapons such as swords is one of the most interesting topics in archaeometallurgy because these objects were manufactured, over the ages, using the highest quality materials and the most advanced technology. The compositional and microstructural characterization of swords, particularly steel swords, can hence allow us to learn about the technological skills reached by different civilizations. Neutron imaging and neutron diffraction are, to the author knowledge, among the best methods to quantify phase composition and microstructure, study morphology, identifying non-metallic inclusions, cracks and defects. Our research team performed a number of experiments using neutron imaging and neutron diffraction to reveal the characteristics of many artifacts from different civilizations, of which the production procedures are not yet fully clear. We studied the complex structure and the thermal and mechanical treatments applied to produce Japanese swords, the microstructure of wootz steel used to produce the “watered silk” pattern on Indo Persian swords, the multilayered Fe-Ni alloys used to produce the Indonesian keris. The results shown in this work allowed us to identify unique features that can shed new light on the manufacturing methods, thus increasing the level of our knowledge about the technological skills of such civilizations.

Speaker: Francesco Grazzi (CNR-IFAC)

2 Texture measurements of archaeological objects at FRM II

Together with the microstructure, polycrystalline materials are characterized by their texture. Texture records the thermo-mechanical history of the materials. Quantitative texture analysis of archaeological materials can therefore help to understand technological processes which were applied on the objects in ancient times.
The main advantage of neutron diffraction over X-ray diffraction arises from the fact that the interaction of neutrons with material is weak, and consequently the penetration depth of neutrons is about 100-1000 times larger than that of laboratory X-ray diffraction. This is particular essential for non-destructive texture analysis of archaeological objects as no additional surface treatments of the samples (e.g. polishing) are necessary.
STRESS-SPEC at FRM II is designed as a state of the art multi-purpose diffractometer for strain and texture analysis. Besides the optimized high neutron flux the available large variability in gauge volume definition systems together with the robotic sample handling option offer high flexibility for bulk or gradient texture measurements.
In this contribution we will first present the instrument and its basic methods for texture/pole figure (and strain) measurement. In addition some successful texture measurements performed at STRESS-SPEC on archaeological objects, such as gold artifacts found at the bronze age rampart of Bernstorf (Bavaria, Germany) and Indian wootz blades will be shown.

Speaker: Michael Hofmann

3 The study of Arms and armour and neutron techniques

Arms and armour generally supply the most interesting topics for analysis because they employ, for the most pressing reasons, the most advanced technology in any culture at any period. The historical artefacts which display the development of arms and armour over the centuries, are frequently the most fragile. So neutron techniques are vital since they offer completely non-invasive methods of analysis.
The Wallace Collection is a national museum which contains (inter alia) the largest collection of princely European armour in London, and one of the most important collections of Oriental armour in Europe. It has been involved with neutron studies for some years.
Three areas of our research will be discussed. Analysis of Medieval European Armour, Identification of armourers' marks, and the forging of Indo-Persian swords, whose metallurgy is both complex, and totally different to European ferrous metallurgy.

Speaker: Alan Williams (The Wallace Collection)

15:15 Coffee Break

Non-destructive characterisation by Scattering and Diffraction Methods

4 Application of neutron-based analytical techniques for studying the manufacturing technique and corrosion of high leaded antique bronze coins

Within a research project 1,200 selected ancient Greek bronze coins from the Coin Cabinet, Kunsthistorisches Museum Vienna (KHM), were studied concerning their state of preservation and manufacturing technique. The coins had been minted during the Roman imperial time (50 to 280 AD) using alloys with high lead and/or tin contents. As a result of their burial followed by unfavourable storage conditions a number of them show progressive whitish corrosion.
Different analytical techniques were used for the study of the corrosion phenomena. The bulk composition of a selected number of objects was investigated by non-destructive neutron diffraction (Rutherford Appleton Laboratory, ISIS, UK) and the presence of lead rich inclusions in a copper rich matrix by applying neutron tomography studies (Paul Scherrer Institute, CH).
Continuative studies focused on the analysis of the corrosion phases (Cu-, Pb-, Cu/Sn-oxides) as well as on the manufacturing techniques of the antique Greek coins. To enable the distinction between different manufacturing techniques – either cast only or cast and minted –, about 20 coins and 15 laboratory test tokens were analysed by bulk neutron texture analysis. Detected changes in the microcrystalline structure of the alloys were related to the mechanical minting processes.
The presentation will give an overview on the capabilities and limitations of the non-destructive investigations by neutron-based analytical techniques used for studying ancient coins.

Speaker: Dr Martina Griesser (Kunsthistorisches Musem Vienna)

5 The metallurgical texture of prehistoric gold artefacts studied by neutron diffraction

The metallurgical texture of archaeological metal objects can give clues about the manufacture of the pieces. Texture analysis with neutrons has therefore been used to study objects from the Bronze Age site of Bernstorf in Bavaria, showing that these objects exhibit a very pure cube texture, which is typical for rolled and annealed fcc metals, a method of productuion hardly imaginable for the Bronze Age. The manner in which the Bernstorf gold foils were produced is thus of some importance for the question of their authenticity. Experiments with gold reference specimens confirmed the cube texture in rolled and annealed specimens and rule out plain hammering. But the question remains whether other manners of making gold foils could also give rise to a cube texture. To clarify this matter, we are presently studying the texture of Bronze Age gold objects from the Bullemheimer Berg and from Hammersdorf, two other Bronze Age sites in Bavaria. These experiments are expected to reveal whether the cube texture is unique for the Bernstorf finds or whether it is more common in ancient gold objects. We are also performing experiments on reference specimens produced under various conditions by hammering and other methods that might have been used by Bronze age goldsmiths. Even if it should be impossible to reach a final conclusion on the Bernstorf finds, the results are an important contribution to the knowledge on the texture of gold objects made by handicraft techniques.

Speaker: Dr Friedrich E. Wagner (Physics Department E15, Technical University of Munich)

6 Neutron diffraction for cultural heritage studies: the Italian Neutron Experimental Station INES

The Italian Neutron Experimental Station INES, located at the pulsed neutron source ISIS (UK), is a general-purpose powder diffractometer built to focus its use on material science and in particular cultural heritage related studies. Thanks to the high penetration power of thermal neutrons, archaeometric measurements performed through neutron diffraction allow for quantitative determination of bulk properties of the sample in a non-destructive way. This opens up the possibility of investigating objects otherwise unsuitable, due to their cultural and/or historical importance. Here we describe the INES instrument and present the results on bronze objects from Sardinia and orichalcum ingots found in Sicily. The orichalcum ingots were previously investigated by XRF showing that the major elements were copper and zinc, in a ratio compatible with the mythological orichalcum, an alloy similar to brass. The neuron diffraction results were compared with the previous results, confirming that they represent one of the most suitable non-destructive approaches for the characterization of metal archaeological artefacts. The obtained results on Sardinian bronze objects showed a very specific procedure for sword forging and allowed for the determination of the bronze composition and microstructure. A comparison with contemporary bronze artifacts produced in the other areas of the Mediterranean area adds important details about the development and exchange of knowledge in this geographic area

Speaker: Francesco Grazzi (CNR-ISC)

Poster Session

7 Using neutron reflectivity to understand the nanoscopic behavior of a synthetic varnish layer during the swelling process by a solvent in an aqueous gel

The riskiest part in the restoration process of paintings is the removal of the old varnish layer. It is subject of controversy between supporters of total removal and supporters of the patina. To remove varnish, the restorer applies solvents and abrades the surface. Often the solvents penetrate into the deeper layers and weaken the structure of the pictorial layer. Essential elements can be extracted. Every year many paintings are being damaged by too thorough cleaning, therefore it important to find solutions to this destructive problem. Many groups are working on this issue but it seems missing an essential element: the comprehension of the fundamental physics governing the restoration process. Understanding the basic polymer physics that underlies these processes will allow designing automated restoration methods that will be completely innocuous to the works of art. In this contribution we will focus on results obtained by neutron reflectometry, chosen because we can measure directly the composition of thin films at liquid interfaces with a resolution of a few Å. We will present recent results, obtained on the FIGARO(ILL) and N-REX(MLZ) reflectometers where we determined the depth profile of solvent in synthetic varnish films usually used by art restorers. We will present the extent and type of varnish swelling just before rupture of this film. The prediction of film rupture will help to ensure a 'safe' restoration process, which will not alter the fragile colored layer.

Speaker: Amélie Castel (Institut Laue Langevin)

8 XRD phase analysis on roman bronze artefacts from Bedaium-Seebruck Potential and limitations using Lab XRD

A bronze horse harness recovered at roman colony “Bedaium” (50-200 AD, now “Seebruck am Chiemsee”) has been investigated by means of x-ray diffraction using a lab-based XRD instrument. The patina of such ancient bronzes impede access to the bulk material with standard Cu-XRD. Depending on it´s thickness, hard Mo radiation with higher penetration depth might enable a non-destructive analysis of the bulk material. In this study we show the potential but also the limitations of such lab XRD systems as a complementary method to neutron diffraction (ND).
The results show that hard x-rays can penetrate thin patina layers to get suitable signals from the bulk. From Rietveld refinement of Mo-XRD data a pure CuSn bronze with a Sn content of 4.3% without any additional alloying elements has been determined. The unit cell of the fcc CuSn solid solution α-phase is increased by 0.8% due to Sn admixture compare to pure Cu. Using Vegard´s law for random substitutional solid solutions, a Sn content of 4.5% has been calculated which is in good agreement with Rietveld results.
Depending on burial conditions and alloy composition, the corrosion products of ancient bronzes also yield information about the composition of the bronze itself. XRD examinations of patina revealed corrosion products mainly of cuprite and malachite which affirm the absence of Pb, Fe and Zn in the alloy.
The results have been verified by ND measurements which allows to investigate mainly the whole bulk material.

Speaker: Armin Kriele (Helmholtz Zentrum Geesthacht)

9 Determination of the elemental composition of archaeological objects by neutron activation analysis (NAA) at the IREN facility and the IBR-2 reactor of the Frank Laboratory of Neutron Physics (FLNP) of the Joint Institute for Nuclear Research (JINR).

NAA of human remains of the XVI-XVII centuries from the Moscow Kremlin necropolises, Russia and medieval glass bracelets found at the Dubna settlement, Russia, was carried out at the FLNP basic facilities – the IREN research facility and the IBR-2 pulsed fast reactor. We studied the rib fragment from the burial place of the son of Tsar Ivan the Terrible, Tsarevich Ivan Ivanovich; the rib fragment from the burial place of Prince Mikhail Vasilyevich Skopin-Shuisky; and elements of hair of the first wife of Tsar Ivan the Terrible, the first Russian Tsarina Anastasia Romanovna. The results of the elemental analysis of human remains, primarily arsenic and mercury, made it possible to clarify the death circumstances of some members of the Russian nobility. The elemental composition of the glasses made it possible to determine presumably the places of production of glass bracelets.
NAA at FLNP JINR is carried out using the automation system for measurement of spectra, which includes a high-purity germanium detector with spectrometric electronics, a sample changer, a control software and the NAA database.

Speaker: Dr Andrey Dmitriev (Joint Institute for Nuclear Research)

10 Neutron imaging of cultural heritage objects at Budapest Neutron Centre

Both archaeologists and conservators can benefit from the investigations of cultural heritage and art objects carried out by means of neutrons. Inner morphology, provenance, manufacturing techniques, workshop assignation, as well as fake identification, conservation or preservation are the usual questions.

Neutrons are perfect tools of cultural heritage studies due to their deep penetration into the matter, and their non-destructive and non-invasive nature. In particular, classical 2D and 3D neutron imaging techniques (tomography/radiography) as well as the coupled prompt-gamma activation analysis and neutron imaging (PGAI-NT) play important role in the careful object characterization. Moreover, the parallel use of neutron and X-ray imaging, as two complementary techniques, is also very informative.

All these methods are available at Budapest Neutron Centre; their recent applications to the cultural heritage science will be presented through case studies.

Speaker: László Szentmiklósi (Centre for Energy Research, Hungarian Academy of Sciences)

19:00 Dinner

Wednesday 20 June

Imaging of Cultural Objects

11 Neutron imaging of cultural heritage objects in Switzerland

Neutron imaging (NI) techniques are particularly suitable for the study of cultural heritage objects as they represent non-destructive and non-invasive testing methods complementary to X-ray methods. Nevertheless, NI methods are relatively rarely used for investigations of such objects, which is partially due to the method’s still low awareness level and the skepticism among museum curators, conservators and archaeologists.
In this presentation, we give an overview on cultural heritage related investigations and projects carried out in collaboration with museums, cantonal archaeology departments and universities in Switzerland. The examples range from mere case studies using simple neutron radiography and tomography (e.g. metallic artefacts from Roman museum Avenches) over combined neutron and X-ray tomography (e.g. sword from Oberwil in collaboration with Swiss national museum (SNM) and archaeology department Zug) to more complex projects over several years (e.g. monitoring of brass wind instruments with SNM, University of the arts Bern and ETH Zurich).

Speaker: David Mannes (Paul Scherrer Institut)

12 Visualization of the sealed contents of a rare medieval reliquary from the historic district of Mainz

It is about a rare 12th century enamelled reliquary from Mainz. This phylacterion is a pendant in the shape of a quatrefoil. It was found in the old town of Mainz in 2008 in an ancient dump. The conservation was performed in the laboratory of the Generaldirektion Kulturelles Erbe (GDKE), Direktion Landesarchäologie Mainz.
In total, the conservation work on the pendant took 500 hours.
The phylacterion is made of gilded copper. Front and verso are enamelled using the technique of email champlevé. The high concentration of mercury revealed by μ-XRF indicates that fire gilding was used.
Since no object was discernable in the interior of the reliquary on radiographs, neutron imaging was performed at the Research Neutron Source Heinz Maier-Leibnitz (FRM II), Technical University of Munich in Garching in order to see if more information could be gained about the contents.
A first short scan directly showed some small objects inside.
The first neutron tomography carried out with a short intensity made the content visible. Inside the phylacterion, different small packages could be seen, around 8 – 10 of them. Around one of these packages, the surrounding textile is also very recognisable. The fabric is folded into a few layers and a thin thread is wrapped around it to keep it together.
The pendant is dated to the last third of the 12th century. This object is one of only four phylacteria known of this type. It is a rare example from controlled excavations.

Speaker: Mr Matthias Heinzel (Römisch-Germanisches Zentralmuseum)

13 Archaeometry at MLZ's PGAA-facility. Spectrometry and structure visualization of Gallo-Roman cultural heritage objects with PGAA and Neutron Tomography

Thanks to the latest developments in neutron sources and advancements in digital signal processing, the capabilities of available gamma spectrometry and neutron imaging sights have significantly improved during the last decades. Instrumental neutron techniques such as Prompt Gamma-ray Neutron Activation Analysis (PGAA) and Neutron Tomography (NT) are effective methods to obtain chemical compositions with good detection limits or visualize internal structures within a sample. As non-destructive analysis methods, they are especially suitable for the investigation of cultural heritage objects and are therefore attractive for the field of archaeometry.
We report on the unveiling and analysis of the insides of various sealed amulet capsules and vessels of the Roman-Germanic Museum (RGM) Cologne using these methods in combination at the PGAA facility of the Heinz Maier-Leibnitz Center (MLZ).

Speaker: Eschly Kluge (Institute of Nuclear Physics at the University of Cologne (IKP))

10:15 Coffee Break

Imaging of Cultural Objects

14 Neutron Imaging Methods for Cultural Heritage at the ANTARES facility at MLZ

The ANTARES neutron imaging facility at Heinz Maier-Leibnitz Zentrum (MLZ) of TUM provides several imaging methods for cultural heritage research. Neutrons help when X-rays cannot penetrate samples, or deliver little to no contrast on the materials involved. Neutrons often provide complementary contrast to x-rays which makes them ideally suited to investigate samples like bones in chalk rock, enamel and dentine in fossil teeth, but also moisture or wood impregnating chemical agents.
Standard neutron radiography provides insight into metallic objects containing organic substances. 3D computed tomography provides three-dimensional information about the internal structure of samples, like fossils embedded in rock.
Bragg edge radiography and tomography is based energy-selective scanning of samples which allows to detect different metallic phases e.g. in medieval swords, providing information on the forging technique.
Neutron grating interferometry (nGI) allows to detect structures (e.g different materials, porosity, inclusions, etc.) below the real space resolution limit of an imaging instrument by analyzing the ultra-small-angle scattering originating from these structures. Hence, this technique allows to indirectly localize structures in the size range from 15 μm to 0.5 μm. By analyzing these data information about the manufacturing process of e.g. pottery can be gained.

The talk will illustrate all methods employed at ANTARES with specific examples.

Speaker: Burkhard Schillinger

15 Neutron imaging options with fission and thermal neutrons at the NECTAR facility

The NECTAR facility at MLZ (NEutron Computed Tomography And Radiography) uses thermal and fission neutrons, the latter by inserting a uranium converter plate in front of the beam tube nozzle, which is unique world-wide. The mean energy of the high-energy spectrum at about 1.8 MeV is obtained via fission reactions in the converter plates placed in front of the window of the SR10 beam tube. The converter plate consist of highly enriched uranium (93% 235U)-silicide with a total weight of 540 g. While the converter is not in the ‘working position’, a thermal neutron beam is available.
The non-destructive inspection performed by neutron radiography and tomography using these two ranges of neutron energy can provide complementary information about the investigated objects. Penetration depth of fission neutrons is much higher as compared to cold or thermal neutrons, and thus gives more insight in large objects and samples containing strongly attenuating elements. In contrast, thermal neutrons provide a much better spatial resolution while still showing higher penetration depth than the cold neutrons available at ANTARES. Thus, due to high penetration depths, NECTAR is a well-suited instrument for investigation of inner structure of large, i.e. archaeological or paleontological objects. Because of the high sensitivity to light elements many applications are related to hydrogen or ammonia storage systems and observation of water distribution in e.g. large wooden samples.

Speaker: Burkhard Schillinger

16 Applications of VGSTUDIO MAX - Visualization and analysis of archeological volume data

Volume Graphics software is an established and powerful tool for the precise analysis and visualization of volume data generated for scientific research. Our application works equally well on data acquired with neutrons, x-rays or other sources. A traditional application field for CT and the subsequent analysis and visualization with VGSTUDIO MAX is the research of ancient mummies. Our latest project involving the mummy from the lady Ta-Cheru successfully combined voxel data from a medical CT with mesh data with colored surface information generated from a 3D scanner. This enabled the creation of stunning visualizations of the object based on the surface colors and (inner) material information, thus producing an authentic digital replica [1] of the mummy. The analysis of CT scans of mummies can also reveal additional details about the life and death of the scanned and mummified individual, as in the case of the mummified kestrel from ancient Egypt [2]. Our various visualization and analysis options have been used to investigate ancient manuscripts [3,4], restore prehistoric figurines, conduct forensic and medical research [5], and characterize different materials. Here, we present the broad range of analysis options across different fields, with a focus on archeological applications.

Speaker: Dr Sandra Engels (Volume Graphics GmbH)

12:15 Lunch

Imaging of Cultural Objects

17 Cultural-heritage research at the Budapest Neutron Centre

Since the launch of its user access program in 1999, the Budapest Neutron Centre (BNC), has always been a key promoter of the collaboration between the cultural heritage domain and neutron scientists. The success of many EU-funded transnational access (TNA) programs (NMI3, NMI3-II, CHARISMA, IPERION CH) as well as the ANCIENT CHARM project highlighted the relevance of the element analysis, imaging and scattering in the non-destructive characterization of valuable artifacts and resulted in over hundred publications. The cultural-heritage-specific access projects promote the multi-technique approach, i.e. to coherently utilize multiple - often complementary - instruments located in a single campus, or even at multiple access providers, in order to answer a specific CH question.

When applying separate instruments at different beamlines, however, the sampling volumes are not necessarily coincident and the penetration depths of the various radiations might also differ, so there is a clear advantage to integrate multiple functionalities into a single instrument and analyze the object at once at the same beamline. This is routinely done at our NIPS-NORMA station with position-sensitive element analysis and cold-neutron imaging (PGAI-NT), offering significant synergies at the data analysis and interpretation stage.

This lecture presents the recent technical, organizational efforts and the significant results made at the BNC using this multi-technique approach.

Speaker: Dr László Szentmiklósi (Centre for Energy Research, Hungarian Academy of Sciences)

18 Revealing the secrets of ancient Japanese helmets

The armour and the sword of the samurai have long been considered to be objects of absolute beauty, from both an aesthetic and a technological point of view. Much literature exists about Japanese swords, but far less is known about the technology of Japanese helmets, the kabuto. In the 15th century when large armies of foot soldiers were becoming more common and fighting on horseback was in decline, the kabuto became one of the most important elements among an armour’s constituents since it allowed the samurai to stand out in the battlefield. From the second half of the 16th century, with the introduction of firearms, the construction technique and style of Japanese armourers changed to increase the protection offered by the armours and helmets.
Here, we present extensive results on the investigation of seven 17th Century kabuto from different schools, conducted thought a combination of neutron diffraction and imaging techniques. Neutron powder diffraction, performed using the INES and ENGIN-X beamlines (ISIS, UK), allowed us to obtain the quantitative phase composition of selected parts of the helmets and to map the residual strain distribution inside a few single platelets along their section. Neutron tomography, carried out at the NEUTRA beamline (SINQ, CH), allowed to determine the inner structure and manufacturing techniques of one kabuto, revealing some otherwise invisible details.

Speaker: Dr Anna Fedrigo (STFC)

19 What was arranged inside Buddhist sculptures centuries ago?

Metallic Buddhist objects are very common in Asian countries and traditionally used until today. States of the Buddha in different forms and manifestations or Stupas (reliquary shrines) are preserved for sometimes for more than 500 years in Asian temples, or in private collections. It is well-known that these hollow-cast objects made of various copper alloys have been filled during a consecration ritual with sacred and symbolic materials when they were completed. These objects are sealed. Therefore this content is not accessible without opening and thus damaging the image and the spiritual essence. We describe the results of examinations of objects from four collections (2 museums, 2 private) using neutron imaging techniques. It has been found out by suitable radiography tests that the outer metal structure and inner consecration substances is best recognized with neutrons, while X-rays must fail due to their reverse contrast features. We will describe how neutron tomography in particular can be used for a complete analysis of the “metallic cover” and the inner content. We will focus on a few important objects and describe how and why the sacred fillings were done centuries ago. The induvial studies represent only a small part of all samples collected word-wide. Owners of similar metallic statues are invited to study the “inner life” and the technique of the object. Neutron tomography is the only method to provide this knowledge.

Speaker: Eberhard Lehmann (PSI)

15:15 Coffee Break

Elemental Analysis and Archeometry

20 Integration of neutron-gamma techniques into neutron instrumentation for the investigation of Cultural Heritage objects

PGAA techniques enjoy unique features of relevance to the materials characterisation, particularly for the non-destructive measurement of elemental (and isotope) composition. We present the development and test experiments on the use of meV to eV neutron beams for Multi-dimensional Prompt-Gamma Activation Analysis, and its integration into imaging and diffraction beam lines at the ISIS pulsed source. Applications to the study of ancient Egyptian objects from the 15th century BCE and on standard bronzes will be discussed.

Speaker: Prof. Roberto Senesi (Università degli Studi di Roma “Tor Vergata”, Dipartimento di Fisica, Centro NAST, and CNR- IPCF Sezione di Messina, and Centro FERMI, Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi)

21 Application of PGAA, in-beam NAA and related Methods in Archaeometry

Prompt gamma activation analysis (PGAA) and in-beam neutron activation analysis (in-beam NAA) offer a non-destructive panoramic analysis with fair detection limits for many elements. Non-destructivity is of extreme importance in archaeometry and cultural heritage research. Due to the low matrix dependence, many different object types can be analyzed – e.g. coins, stone artefacts and glasses. At the PGAA instrument of MLZ, the current research in this field focuses on provenance analysis of archaeological findings, investigation of the production methods of ancient objects, conservation-restoration research and reverse engineering of ancient aqueduct systems. The instrument makes possible the combination of different techniques. PGAA and in-beam NAA are complementary for the determination of several elements, so that the combination increases the number of analyzed elements which is important for provenance analysis. A cold-neutron tomography setup provides additional information about the internal structure of small objects and with prompt gamma activation imaging (PGAI) one can perform spatial resolved PGAA. We will present an overview about our current projects and the possibilities of the PGAA facility in archaeometry and cultural heritage research.

Speaker: Christian Stieghorst (TUM / FRM II)

22 Determination of element composition of archaeological objects by neutron resonance capture analysis

The method of Neutron Resonance Capture Analysis (NRCA) is currently being developed in the Frank Laboratory of Neutron Physics (FLNP) for the purpose of determination of the element composition of samples. The method is based on registration neutron resonances in radiative capture and measurement the yield of reaction products in these resonances. The method is non-destructive, the induced activity of the sample is practically absent. All this makes it promising for research of archaeological artifacts and objects of cultural heritage.
These measurements have been performed for a number of archaeological objects in collaboration with Institute of Archaeology RAS at the pulsed neutron source IREN of FLNP. One of the samples is a fibula from Podbolotyevsky burial ground (10th century AD) in the Vladimir Region. The element composition determined by analysis can be used for the identification a territory where the fibula was made. The relevant investigation about the medallion of ancient Russian time (XII - first half of XIII centuries) will also be presented.

Speaker: Nina Bazhazhina (Joint Institute for Nuclear Research)

Poster Session

19:00 Dinner

Thursday 21 June

Elemental Analysis and Archeometry

23 Neutron versus x-ray imaging. Selected case studies at the National museums in Berlin using radiography, macro-x-ray fluorescence mapping and computed tomography

In this presentation we emphasize the complementary of neutron and x-ray methods in cultural heritage science on the basis of selected study cases on museum objects from different collections of the national museums in Berlin.
Information on the genesis of different easel paintings of the collection of the Gemäldegalerie (Painting Gallery), Staatliche Museen zu Berlin-Stiftung Preußischer Kulturbesitz (SMB-SPK) gained by X-ray radiography and macro x-ray fluorescence (MA-XRF) mapping are compared to imaging by neutron autoradiography.
Analogously, the special performances of x-ray and neutron computed tomography are highlighted based on the non-invasive study of 3D ivory, wooden and metal objects from different archaeological and object collections, namely the Ägyptische Museum (Egyptian Museum), the Vorderasiatisches Museum (Museum of the Ancient Near East) and the Kunstgewerbemuseum (Museum of Decorative Arts) of the SMB-SPK.

References:

Osterloh et al., Neutron computed tomography for preserving charred wooden cultural objects, Annual report FRMII, TUM (2018)
Alfeld et al., Scanning macro-X-ray fluorescence analysis and Neutron Activation Auto Radiography: Complimentary imaging methods for the investigation of historical paintings, Berliner Beiträge zur Archäometrie, Kunsttechnologie und Konservierungswissenschaft (BBA) 23 (2015) 9-14
di Matteo et al., Investigation of Ancient Egyptian Metallic Artefacts by Means of Micro-Computed Tomography, BBA 23 (2015) 79-84

Speaker: Dr Ina Reiche (Rathgen-Forschungslabor, Staatliche Museen zu Berlin-Stiftung Preussischer Kulturbesitz)

24 Tracing organic consolidants in wooden artefacts with neutron tomography

Ancient and historic wooden artefacts are consolidated by soaking with organic consolidants. Some consolidants, as carbolineum, showed undesired effects and are to be removed. Both, introduction and removal process benefit from a known distribution of the consolidant inside of the object.
X-ray tomography is insufficient for this purpose since both, the wooden matrix and the impregnating chemicals consist of organic substances composed mainly out of carbon and hydrogen. In difference, materials rich in hydrogen are rather effective in absorbing neutrons. This makes neutron radiological technologies predestine for studying the distribution of applied organic substances in wooden objects.
To demonstrate both, the purpose of the interrogation with neutrons and the range of objects that could be investigated, four different examples of objects are presented here: 1) small wooden pieces of ship wrecks (< 2 cm thickness) interrogated with cold neutrons (0.5 meV at the ANTARES facility of the FRM II in Garching) to demonstrate the potential and the limitation of using low energy neutrons, 2) pieces of charred wood to study the impregnation with a consolidant (fission neutrons 1.8 MeV at the NECTAR facility of the FRM II), 3) a wooden statue soaked with carbolineum (same facility) and 4) a smaller wooden figure of a scull heavily soaked with carbolineum which was too tight for the fission neutrons with accelerator neutrons (broad range about 5.5 MeV at the PTB in Braunschweig).

Speakers: Amélie Nusser (Rathgen-Forschungslabor), Kurt Osterloh (BAM Federal Institute for Materials Research and Testing), Ina Reiche

25 PGAA and NAA study of Roman Haltern 70 amphorae from ancient Lusitania and Baetica

Amphorae of the Haltern 70 type were produced mainly in the Roman provinces of Hispania Baetica and Lusitania in the south of modern Spain during the second half of the first century BC and the first century AC. On the other hand, a large number of sherds of such amphorae was found in excavations of a Roman settlement at Castro do Vieito in the northwest of Portugal. Presumably, these amphorae were used for transporting agricultural produce from the south to supply the Roman military stationed in the north. To test this hypothesis, we studied the element content of about 120 amphora sherds from Castro do Vieito and from the known kiln sites in Baetica and Lusitania, nowadays the Algarve coast and the valleys of the Guadalquivir river and the Rio Tinto, as well as the coast near Cadiz and Algeciras. By PGAA and in-beam NAA at the FRM2 reactor of the Technical University of Munich about 20 element contents were determined for each sherd. The aim of this work is to find similarities in the element contents of samples from the kiln sites and from Castro do Vieito that could prove that the amphorae from Castro do Vieito are from the south of Spain and possibly from which kiln site they preferentially came. The data are still being analyzed, but first results already seem to confirm this archaeological expectation. The data for Haltern 70 amphorae from the kiln sites may also help in the future to identify the origin of Haltern 70 amphorae found at other sites.

Speaker: Dr Benilde F.O. Costa (CFisUC, Physics Department, University of Coimbra, P-3004-516 Coimbra, Portugal )

10:15 Coffee Break

Elemental Analysis and Archeometry

26 Neutrons and Numismatics. A cooperation to uncover ancient history

Numismatics is a discipline extremely open to different influxes and approaches, spanning from archaeology to history, from statistics to economics. While for certain ages we have enough documentary sources to understand social and economic processes behind the production of coins, for other historical periods we need different research approaches. In these cases, materials whose coins are made could reveal large amounts of data otherwise inaccessible.
In this presentation some case studies will be shown, in order to offer a brief but complete overview of the issues a numismatists could face with the help of neutron-based techniques. Particular emphasis will be given to a research project concerning Iron-age coins produced by pre-Roman tribes settled in northern Italy. A selection of different types of silver drachmas coming from public and private collections has been analysed with neutron diffraction (ND-TOF) and neutron activation (PGAA) techniques. The results obtained have been related with the military efforts of pre-Roman peoples in the decades around the second Punic war and, afterwards, with the increasing influence of Rome in the Po valley.

Speaker: Dr Jacopo Corsi (University of Turin, Physics Department)

27 Applications of Instrumental Neutron Activation Analysis (INAA) for Culture and Art at FRM II

With its diverse irradiation positions and very pure thermal neutron flux, the reactor FRM II offers good opportunities for investigations of chemical element composition in samples from different research fields. The reasons for using the instrumental NAA are based on the advantages of simple sample preparation without chemical handlings, high sensitivity, multi-element capability from the main and minor elements to the trace elements and non-destructiveness. The so-called “finger print” method of analysis of element composition can bring light into the darkness of the puzzles of archaeological materials or other art objects and give us more details about their provenances and relationships.
Some interesting objects investigated in the last years, such as old ceramics from the Far East, a European medieval bronze object, jewels of gold and pigments used in the renaissance and in the modern time will be introduced in our presentation. Within a special research program designed for high school students namely TUMKolleg, we are just starting a new project for analysis of ceramic sherds directly from the excavation site in Naga, Sudan. Naga was an important city of the Kingdom of Meroe, which was a neighbor and also a powerful rival of Ptolemaic and Roman Egypt in that time. The city has remained untouched under the earth for almost two thousand years. Now, Naga has become a wonderful research ensemble for the archaeologists since the excavation in 1990s.

Speaker: Dr Xiaosong Li (Radiochemie TU München)

28 Coupled Neutron reflectivity / rheology for safe removal of synthetic varnish layer on easel paintings

Varnish on easel painting has two objectives: protect the colored layer from external impact and saturate the colors of the pigments (esthetic role). Varnish is the first layer exposed to light, dust and other deteriorating factors. Thus, easel paintings loose their visual appearance making the observation and appreciation of the details of the artwork difficult. In order to reverse these processes, ancient paintings are periodically restored. The restoration of the pictorial layer is a major transformation, which involves mainly the dissolution and replacement of the varnish that covers the paint layer, and may alter considerably the composition and the cohesion of this composite material. During the 20th century a large number of paintings have been damaged, not through war or natural cataclysms but through restoration operations. There is an urgent need for a deeper understanding of the processes that are employed in restoration operations. We present recent results on the nanoscopic mechanisms for swelling and dissolution of a Laropal A81 varnish film by the transfer of a small amount of solvent applied through an aqueous gel. For this, neutron reflectometry (NR) coupled insitu with rheology was used to investigate directly the behavior of thin films at liquid interfaces with a resolution of a few Å during its swelling, breaking and dissolution. We show a signature for film rupture and dissolution via surface heterogeneity.

Speaker: Ms Amélie Castel (Institut Laue Langevin)

12:15 Lunch

14:30 Conference Trip and Dinner

We will go by bus to the open-air exhibition Glentleiten and take a tour there before we stroll around.

18:30 Conference Trip and Dinner

For Dinner we will go by bus from Glentleiten to the Kreut Alm.

Friday 22 June

09:00 Departure