The spectrometric properties of several hydrophthalate crystals (KAP, RbAP, TlAP, and CsAP) are studied. Especially investigated is cesium hydrophthalate for which little information is available in the literature. Experimental... more
The spectrometric properties of several hydrophthalate crystals (KAP, RbAP, TlAP, and CsAP) are studied. Especially investigated is cesium hydrophthalate for which little information is available in the literature. Experimental measurements of rocking curves at 1000 and 2500 eV performed on the SB3 beamline of Super ACO storage ring (LURE-Orsay) are presented. The experimental results are compared with calculations made with a new version of BRAGG, a preprocessor of the ray-tracing SHADOW. This improved version allows to generate rocking curves of any crystal structures. The results of the perfect crystal model matches well with the experimental observation. Among the selected crystals CsAP shows the highest reflectivity.
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The silicon photodiode array Hamamatsu S3901 series (1024, 25 μm pixel) were primarily developed for the visible-UV spectral range, mainly for photon wavelengths between 200 and 1100 nm. By utilizing it without a quartz window, it is... more
The silicon photodiode array Hamamatsu S3901 series (1024, 25 μm pixel) were primarily developed for the visible-UV spectral range, mainly for photon wavelengths between 200 and 1100 nm. By utilizing it without a quartz window, it is demonstrated that this sensor can be used for x rays, especially in the 1–10 keV range. Experimental measurements of the absolute detection efficiency of the photodiode array between 1.5 and 12 keV are presented. The experiments were performed on an x-ray tube-excited secondary targets and on the SB3 beamline at the Super ACO storage ring (LURE-Orsay). The measured spectral efficiency is compared with the results of a simple model calculation based on the data given in the Hamamatsu note. The simulation is in good agreement with the experimental data for a silicon active depth of 6 μm and a silicon dioxide passivation layer of 5 μm. The linearity is better than 1% and the spatial resolution is estimated to be 120 μm.
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Les pigments préhistoriques sont formés à partir de composés naturels tels les d’oxydes de fer ou les oxydes de manganèse. Ils ont été collectés par les hommes préhistoriques dans leur environnement proche ou parfois à de grandes... more
Les pigments préhistoriques sont formés à partir de composés naturels tels les d’oxydes de fer ou les oxydes de manganèse. Ils ont été collectés par les hommes préhistoriques dans leur environnement proche ou parfois à de grandes distances. Connaître leur provenance géographique, ou à défaut établir des relations entre matière première retrouvée en fouille et objets archéologiques décorés, pourraient permettre de retracer la mobilité des populations et d’appréhender les choix techniques opérés ou la mise en place des décors.Ces relations et provenances peuvent être établies à partir de la composition chimique des matériaux employés. Il a été notamment démontré, que pour les obsidiennes ou les minéraux précieux tels les grenats ou les rubis, la nature et la concentration des éléments traces sont caractéristiques des milieux géologiques dans lesquels ils ont été formés. Dans le cadre de Madapca, la même démarche a été appliquée aux pigments préhistoriques. Elle s’appuie principalement sur la méthode d’analyse non destructive PIXE (Particule Induced X-ray Emission) et a été développée pour des pigments provenant des sites d’Arcy sur Cure (Châtelperronien, 32 000 BP) et de l’Abri Pataud (niveau Proto-Magdalénien, 22 000 BP). L’analyse élémentaire des éléments majeurs, mineurs et traces a permis de mettre en évidence des groupes de pigments de composition distincte au sein des niveaux archéologiques étudiés, et donc l’utilisation de sources de matière premières différentes. Dans le cas de l’Abri Pataud (Dordogne), il a été possible d’établir des correspondances entre la composition chimique des blocs de matière première composés d’oxydes de fer et celle des décors peints sur des éléments mobiliers ou sur les écailles ornées provenant de l’effondrement du plafond de l’abri. Dans le cas d’Arcy-sur-Cure (Yonne), nous avons pu montrer que la teneur en éléments traces variaient en fonction de la provenance des blocs de pigments rouges et noirs, trouvés en nombre dans la grotte du Renne. Cette étude démontre l’intérêt des techniques de spectrométrie X pour la différentiation des matériaux colorants utilisés en contexte préhistorique.Peer reviewe
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Known as lead white, lead carbonates were used as white pigment or cosmetics from the 4th century BC to the 20th century AD. Lead white was produced by the corrosion of metallic lead by vinegar and horse manure up to the 19th c. In order... more
Known as lead white, lead carbonates were used as white pigment or cosmetics from the 4th century BC to the 20th century AD. Lead white was produced by the corrosion of metallic lead by vinegar and horse manure up to the 19th c. In order to document the incorporation of carbon in the corrosion mechanism, lead carbonates were produced in the laboratory under monitored experimental conditions using materials with different isotope signatures in 14C and 13C. Six experimental setups were defined combining vinegar, acetic acid, horse manure and fossil CO2 gas. The corrosion products were characterized by X-ray diffraction. 14C content and δ13C values of the initial reactants and the final products were measured by accelerator and isotopic ratio mass spectrometry (AMS and IRSM). The reaction between lead and vinegar or acetic acid resulted in lead acetates with a carbon isotopic signature close to that of the corrosive reagent. In the presence of CO2, the carbonatation reaction occurred a...
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Study of prehistoric art is playing a major role in the knowledge of human evolution. Many scientific methods are involved in this investigation including chemical analysis of pigments present on artefacts or applied to cave walls. In the... more
Study of prehistoric art is playing a major role in the knowledge of human evolution. Many scientific methods are involved in this investigation including chemical analysis of pigments present on artefacts or applied to cave walls. In the past decades, the characterization of coloured materials was carried on by taking small samples. This procedure had two main disadvantages: slight but existing damage of the paintings and limitation of the number of samples. Thanks to the advanced development of portable systems, in-situ analysis of pigment in cave can be now undertaken without fear for this fragile Cultural Heritage. For the first time, a portable system combining XRD and XRF was used in an underground and archaeological environment for prehistoric rock art studies. In-situ non-destructive analysis of black prehistoric drawings and determination of their composition and crystalline structure were successfully carried out. Original results on pigments used 13,000 years ago in the c...
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ABSTRACT In 2001, five French public organizations (CNRS, CEA, IRD, IRSN, and the Ministère de la Culture) signed an agreement to purchase a new accelerator mass spectrometer to provide radiocarbon dating services at the national level.... more
ABSTRACT In 2001, five French public organizations (CNRS, CEA, IRD, IRSN, and the Ministère de la Culture) signed an agreement to purchase a new accelerator mass spectrometer to provide radiocarbon dating services at the national level. The Laboratoire de Mesure du Carbone 14 (LMC14) was set up in Saclay (France) around ARTEMIS, an AMS system based on a 3MV Pelletron from NEC and installed in early 2003. In 2015, the LMC14 joined the Laboratoire des Sciences du Climat et de l’Environnement, making it possible to develop research projects in addition to the service activity and since 2021, the LMC14 has been a member of the IAEA Collaborating Centre “Atoms for Heritage” at the Université Paris-Saclay. Since 2003, 70,000 samples have been measured. Two-thirds of the samples have been prepared on site and one-third in two associated laboratories in Paris and Lyon. Over the past years, the LMC14 has participated in several international inter-comparisons and has continuously improved its capabilities by developing new protocols for preparation and measurement. In this paper, the radiocarbon dating services of the last 20 years for research institutions, museums and environmental monitoring are reviewed and recent results from environmental and archaeological research programs are highlighted.
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Forgeries exist in many fields. Money, goods, and works of art have been imitated for centuries to deceive and make a profit. In the field of Cultural Heritage, nuclear techniques can be used to study art forgeries. Ion beam analysis... more
Forgeries exist in many fields. Money, goods, and works of art have been imitated for centuries to deceive and make a profit. In the field of Cultural Heritage, nuclear techniques can be used to study art forgeries. Ion beam analysis (IBA), as well as 14C accelerator mass spectrometry (AMS), are now established techniques, and the purpose of this paper is to report on their capacity to provide information on ancient, as well as modern, forgeries. Two case studies are presented: the production of silver counterfeit coins in the 16th century and the detection of recent forgeries of 20th century paintings. For the counterfeit coins, two silvering processes were identified by IBA: mercury silvering (also called amalgam silvering or fire silvering) and pure silver plating. The discovery of 14 mercury silvered coins is an important finding since there are very few known examples from before the 17th century. In the detection of recent forgeries, among the five paintings examined, 14C dati...
Research Interests: Physics and Counterfeit
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The study of iron reinforcements used in the construction of Notre-Dame de Paris offers a glimpse into the innovation that took place on this building site in the mid-12th century, adapting metal to create a novel architecture. The... more
The study of iron reinforcements used in the construction of Notre-Dame de Paris offers a glimpse into the innovation that took place on this building site in the mid-12th century, adapting metal to create a novel architecture. The restoration of the monument after the 2019 fire offered unique possibilities to investigate its iron armatures and to sample 12 iron staples from different locations (tribunes, nave aisles and upper walls). Six of them were dated thanks to the development of an innovative methodology based on radiocarbon dating. They reveal that Notre-Dame is the first known Gothic cathedral where iron was massively used as a proper construction material to bind stones throughout its entire construction, leading to a better understanding of the master masons’ thinking. Moreover, a metallographic study and slag inclusion chemical analyses of the staples provide the first study of iron supply for a great medieval Parisian building yard, renewing our understanding of iron ci...
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International audienceLes matériaux ferreux ont alimenté différents domaines de la culture matérielle Khmer et participé au développement de son empire entre le IXème et le XVème siècle. Outils, armes, renforts pour l’architecture ou la... more
International audienceLes matériaux ferreux ont alimenté différents domaines de la culture matérielle Khmer et participé au développement de son empire entre le IXème et le XVème siècle. Outils, armes, renforts pour l’architecture ou la sculpture en bronze sont autant de témoins issus de processus de production et de diffusion susceptibles d’apporter un éclairage nouveau sur les échanges économiques à l’époque angkorienne. En combinant études archéologiques, technologiques, chronologiques et de provenance sur deux grandes zones de production de fer et un grand nombre d’objets, le projet ANR IRANGKOR « production, circulation, et consommation du fer dans le royaume khmer entre le IXème et le XVème siècle (Angkor, Cambodge) » a apporté de nouveaux éléments pour comprendre l’évolution de la production de biens matériels à cette époque en Asie du sud-est. Dans cette approche intégrée, la datation radiocarbone directe des objets ferreux a permis de compléter les repères chronologiques fournis jusqu’alors par l’histoire de l’art ou l’épigraphie dans un contexte où manquent souvent les matériaux habituellement utilisés en datation. Les datations de renforts architecturaux ont en particulier permis de « revisiter » la chronologie de certains temples et leur attribution aux différents rois bâtisseurs. Les datations réalisées sur les armatures de plusieurs statues en bronze ont constitué une véritable première pour ces objets qui n’avaient jamais pu faire l’objet de datations directes et pour lesquels les historiens d’art manquaient parfois d’éléments discriminants.Nous présenterons ici les résultats les plus marquants parmi les 70 datations réalisées sur des objets ferreux provenant d’ensembles architecturaux, de sites archéologiques et de musées
Research Interests: Humanities and Art
ABSTRACTSpermaceti is a waxy substance found in the head cavities of sperm whales (Physeter macrocephalus and P. catodon). This substance had a variety of commercial applications from the end of the 18th to the beginning of the 20th... more
ABSTRACTSpermaceti is a waxy substance found in the head cavities of sperm whales (Physeter macrocephalus and P. catodon). This substance had a variety of commercial applications from the end of the 18th to the beginning of the 20th century, such as candles, soap, cosmetics and other compounds. Spermaceti was also occasionally used as wax for modeling sculptures. In order to date such artworks the marine reservoir effect (MRE) has to be considered. The chemical library of the Muséum national d’Histoire naturelle (Paris, France) contains samples of spermaceti studied by the French chemist M. E. Chevreul (1786–1889) at the beginning of the 19th century. Eight samples of substances preserved in their original containers were 14C dated. According to the whaling practices and the publications of Chevreul, we estimated that the spermaceti samples came from whales caught between 1805 and 1815. AMS 14C dating results are from 550 to 1180 ± 30 BP, R values between 393 and 1023 (± 34) 14C yr ...
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International audienceThe Preuschdorf coin hoard, found in the Alsace, offered the opportunity to study silver-plated coins from the 16th to 17th century AD. 36 silvered coins have been studied and two silvering processes have been found:... more
International audienceThe Preuschdorf coin hoard, found in the Alsace, offered the opportunity to study silver-plated coins from the 16th to 17th century AD. 36 silvered coins have been studied and two silvering processes have been found: amalgam silvering for 44 % of the coins and a thin layer of pure silver for 56 % of the coins. The majority of the coins silvered with mercury were struck in Palatinate whereas those with pure silver come from the city of St. Gallen in Switzerland. In order to confirm these technologies, replications have been undertaken at the archaeological experimental platform in Melle (Deux Sèvres, France). The combination of the observation of non-restored coins and of the replication production gives a good representation of the silvering processes used in the Holy Roman Empire in the 16th century for producing counterfeit coin
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The Cave of Rouffignac (Dordogne, France) is a Paleolithic rock art site which contains numerous black drawings (mammoths, bison, rhinoceros, horses, ibexes . . .). Although no direct dating has been carried out to date, the artworks of... more
The Cave of Rouffignac (Dordogne, France) is a Paleolithic rock art site which contains numerous black drawings (mammoths, bison, rhinoceros, horses, ibexes . . .). Although no direct dating has been carried out to date, the artworks of this cave are generally connected with the Magdalenian Culture.
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PIXE analysis is usually carried out by using protons as the incident projectiles. Protons generally present the advantages of large penetration depth and high ionization power. However, the use of heavier ions can be useful in a specific... more
PIXE analysis is usually carried out by using protons as the incident projectiles. Protons generally present the advantages of large penetration depth and high ionization power. However, the use of heavier ions can be useful in a specific context. Deuterons or helium-4 ions produce ...
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... English: Gallo-Roman; gilding; goldsmithing; jewelry; Merovingian; Roman; scientific analysis Subject Label: Metals and metallurgical by-products Abstract: Results of scientific analysis of the gilding covering some 20 Gallo-Roman and... more
... English: Gallo-Roman; gilding; goldsmithing; jewelry; Merovingian; Roman; scientific analysis Subject Label: Metals and metallurgical by-products Abstract: Results of scientific analysis of the gilding covering some 20 Gallo-Roman and Merovingian pieces of jewelry from the ...
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In order to test the glazing protection efficiency on historic sites, VIDRIO programme gave the opportunity to expose model painted glasses as "grisaille sensors" included in stained-glass windows copy panels. These alkali-lime... more
In order to test the glazing protection efficiency on historic sites, VIDRIO programme gave the opportunity to expose model painted glasses as "grisaille sensors" included in stained-glass windows copy panels. These alkali-lime silica glasses, reproducing the ancient glass ...
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ABSTRACTVery little is known about the manufacturing and use of ancient Egyptian instruments, and their discovery is very rare. An extensive radiocarbon (14C) dating program has been conducted on 25 ancient Egyptian musical instruments... more
ABSTRACTVery little is known about the manufacturing and use of ancient Egyptian instruments, and their discovery is very rare. An extensive radiocarbon (14C) dating program has been conducted on 25 ancient Egyptian musical instruments currently held at the Louvre Museum (musée du Louvre) and the Lyon Museum of Fine Arts (musée des Beaux-Arts de Lyon). This study includes cordophones (harps, lyres, lutes), membranophones (drums, tambourines), idiophones (clappers, crotales), as well as wind instruments (oboe) that have entered the museum collections during the 19th century or the first half of the 20th century; consequently, the original archaeological contexts of their discoveries are poorly understood. Approximately 50 14C dates enable drawing a general overview of the instruments manufacturing. A wide variety of wood material has been identified, representing both indigenous species and imported species. Results indicate that the native flora of Egypt was exclusively used until t...
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Utiliser des herbiers pour restituer la teneur en 14C de l’atmosphère en Égypte aux XVIIIe-XIXe siècles : c’est le challenge de ce projet. L’enjeu est d’évaluer de possibles déviations par rapport à la courbe de calibration 14C... more
Utiliser des herbiers pour restituer la teneur en 14C de l’atmosphère en Égypte aux XVIIIe-XIXe siècles : c’est le challenge de ce projet. L’enjeu est d’évaluer de possibles déviations par rapport à la courbe de calibration 14C internationale IntCal afin de préciser les datations 14C d’artéfacts archéologiques, et d’approfondir la chronologie de la Méditerranée orientale des IIIe et IIe millénaires.
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La datation directe d'alliages ferreux par le carbone 14 : les renforts architecturaux et les armatures de statues en bronze etudies dans le cadre du projet ANR IRANGKOR (dir. S. Leroy), le fer a Angkor. Depuis 2015, le projet... more
La datation directe d'alliages ferreux par le carbone 14 : les renforts architecturaux et les armatures de statues en bronze etudies dans le cadre du projet ANR IRANGKOR (dir. S. Leroy), le fer a Angkor. Depuis 2015, le projet International ANR IRANGKOR apporte un eclairage nouveau sur les reseaux de production et de distribution du fer dans l'empire khmer du 9eme au 14e siecle. Le corpus d'etude, constitue de plus d'une centaine d'objets-renforts architecturaux provenant des temples et monuments d'Angkor, outils, armes et armatures de statues en bronze-ainsi que de minerais preleves dans les grandes regions de production a fait l'objet d'etudes typologiques, d'analyses metallographiques et chimiques pour tenter d'identifier les grandes zones de provenance et les axes de circulation durant toute la periode angkorienne. Dans cette etude diachronique, le calage chronologique de certains elements du corpus a ete realise par datation carbone 14 de...
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The main objective of this report is to present the dating process routinely applied to different types of samples at the Laboratoire de Mesure du Carbone 14 (LMC14). All the results and protocols refer to our procedures over the last 5... more
The main objective of this report is to present the dating process routinely applied to different types of samples at the Laboratoire de Mesure du Carbone 14 (LMC14). All the results and protocols refer to our procedures over the last 5 years. A description of the sorting and chemical pretreatments of the samples as well as the extraction and graphitization of CO2 are reported. Our last study concerning the degradation of the blank level according to the storage time of the targets between graphitization and accelerator mass spectrometry (AMS) measurement is also presented. This article also provides information on how to submit a valid laboratory sample. We give details relating to sampling procedures on site as well as contamination issues relative to the 14C dating methodology.
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We report on the capacity of AMS radiocarbon dating to play a decisive role in fighting against the illicit trade in art. In the framework of a current police investigation, where previously unseen paintings were discovered in a... more
We report on the capacity of AMS radiocarbon dating to play a decisive role in fighting against the illicit trade in art. In the framework of a current police investigation, where previously unseen paintings were discovered in a restorer's workshop by the French Central Office for the Fight against Illicit Trafficking in Cultural Property (OCBC), we demonstrated that two paintings alleged to be by Impressionist and Pointillist artists had in fact been painted recently. Our results were based on the excess of 14C derived from atmospheric nuclear tests detected in the fibers used to make the canvas. By combining AMS 14C absolute dating and the fine precision of the post-bomb atmospheric calibration curve, we established a clear chronological context for the production of these forgeries. 14C content of the fibers revealed that the canvases were manufactured in 1956-1957 or, more likely, after 2000. As a result, absolute dating proves unambiguously that the Impressionist and Pointillist paintings are forgeries since they were not painted at the beginning of the 20th century by the alleged artists, who died in the 1940s.
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We report on the capacity of AMS radiocarbon dating to play a decisive role in fighting against the illicit trade in art. In the framework of a current police investigation, where previously unseen paintings were discovered in a... more
We report on the capacity of AMS radiocarbon dating to play a decisive role in fighting against the illicit trade in art. In the framework of a current police investigation, where previously unseen paintings were discovered in a restorer's workshop by the French Central Office for the Fight against Illicit Trafficking in Cultural Property (OCBC), we demonstrated that two paintings alleged to be by Impressionist and Pointillist artists had in fact been painted recently. Our results were based on the excess of 14C derived from atmospheric nuclear tests detected in the fibers used to make the canvas. By combining AMS 14C absolute dating and the fine precision of the post-bomb atmospheric calibration curve, we established a clear chronological context for the production of these forgeries. 14C content of the fibers revealed that the canvases were manufactured in 1956-1957 or, more likely, after 2000. As a result, absolute dating proves unambiguously that the Impressionist and Pointillist paintings are forgeries since they were not painted at the beginning of the 20th century by the alleged artists, who died in the 1940s.
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Elabore et utilise par l’homme depuis plusieurs millenaires, le fer a fait l’objet de nombreuses etudes permettant de reconstituer les processus de fabrication et sa circulation a travers le monde et les epoques. Sa caracterisation par... more
Elabore et utilise par l’homme depuis plusieurs millenaires, le fer a fait l’objet de nombreuses etudes permettant de reconstituer les processus de fabrication et sa circulation a travers le monde et les epoques. Sa caracterisation par des procedes physico-chimiques a complete les etudes archeologiques en apportant des indices determinants sur l’origine des minerais et les lieux et modes de fabrication et de transformation. Par contre, son emploi comme materiau de datation est reste tres marginal. Pourtant, le fer contient du carbone incorpore dans la loupe de fer au moment de la reduction du minerai et provenant du charbon de bois utilise comme combustible dans le four de reduction. Cependant, la faible teneur en carbone et l’heterogeneite des aciers anciens ont limite jusqu’a maintenant leur utilisation comme materiau de datation pour le carbone 14. Lors de la 2eme journee REFRAIN en 2014, notre collegue Stephanie Leroy, avait presente la methode fiable et originale developpee par...
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1 : C2RMF UMR171 CNRS, Centre de Recherche et de Restauration des Musees de France, Palais du Louvre, Porte des Lions, 14 quai Francois Mitterrand, 75001 Paris, France. 2 : CEA, DEN, Service de Recherches de Metallurgie Physique,... more
1 : C2RMF UMR171 CNRS, Centre de Recherche et de Restauration des Musees de France, Palais du Louvre, Porte des Lions, 14 quai Francois Mitterrand, 75001 Paris, France. 2 : CEA, DEN, Service de Recherches de Metallurgie Physique, Laboratoire JANNUS, 91191 Gif-sur-Yvette, France, lucile.beck@cea.fr 3 : Museum National d'Histoire Naturelle, Departement de Prehistoire, UMR 7194 MNHN, 1 rue Rene Panhard, 75013 Paris, France 4 : Centre Europeen d'Archeometrie (CEA), Institut de Physique Nucleaire, Atomique et spectroscopie (IPNAS), Universite de Liege (ULg), Sart Tilman B15, B-4000 Liege, Belgium
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L'etude presentee ici illustre les apports, les limites et le potentiel des methodes essentiellement micro-destructives pour la connaissance et la conservation de l'art mobilier prehistorique. Ces analyses ont ete realisees sur... more
L'etude presentee ici illustre les apports, les limites et le potentiel des methodes essentiellement micro-destructives pour la connaissance et la conservation de l'art mobilier prehistorique. Ces analyses ont ete realisees sur les blocs de pigments provenant du Grand Abri et de la grotte Blanchard de La Garenne qui constituent les sites de reference du Magdalenien moyen "a navettes". Les resultats obtenus sur les pigments rouges, jaunes et noirs par DRX montrent des ensembles coherents de pigments relativement purs d'hematite, de goethite et de pyrolusite. Les analyses complementaires de MET et MEB-FEG ont permis de demontrer la presence de chauffage pour certains echantillons rouges d'hematite. Certains echantillons presentent des signes de chauffage a relativement haute temperature (> 650°C) (figures de recristallisation d'hematite), ce qui n'avait encore jamais ete observe sur des echantillons archeologiques. Ceci impliquerait l'utilisati...