AGLAE Facility Research Articles

Non-invasive analyze of boron and lithium in 18th century Chinese porcelain enamel and glaze: A PIXE/PIGE study

In enamelling technology, the natural (raw) materials used before the middle of the 19th century combine by nature different elements whose role in the process can be important even in small quantities. Some of these elements – particularly boron, lithium – are difficult to measure non-invasively and are therefore rarely analyzed. Boron and lithium, often used as additional flux in glazes, were quantified by PIXE and PIGE analysis with the extracted beam of the New AGLAE facility in 18th century porcelains samples, French soft-paste from the Manufacture royale de Sèvres and Chinese hard-paste from the reign of the Qing dynasty. The results were compared to previous conclusions made using SEM/EDS and pXRF in order to assert the presence of boron, previously suspected by Raman microspectroscopy, and to detect the presence of lithium, both provided by a particular flux (borax), mentioned in the historical French and Chinese enamel recipes.

Chemical Analysis of prehistoric pottery complex of Valcorrente - Sicily (Italy)

Abstract This paper is aimed at studying different pottery sherds excavated in the site of Valcorrente, located in Sicily, occupied in three main periods, dating respectively to the end of the Neolithic period, to the end of the Chalcolithic period, and to the Early Bronze Age. The chemical composition of the pottery sherds has been analysed with Ion Beam techniques at AGLAE facility at Centre de Recherche et Restauration des Musées de France and the results have been treated with principal component analysis in order to extract indications about the ceramic production technology in the area and the evolution in time.

Glass-gems from the National Archaeological Museum in Aquileia: a PIXE/PIGE compositional study

Abstract A total of 100 investigated coloured/colourless opaque and transparent glass-gems of the National Archaeological Museum of Aquileia (Italy) have been analyzed with a non-invasive approach, at the AGLAE facility (Centre de Recherche et Restauration des Musées de France - C2RMF), located at the Palais du Louvre in Paris (France). The collection represents a “unicum” in terms of number of finds and richness of typologies. Almost all the glass-gems were discovered in the Roman site of Aquileia, known as an important center of glass working, and are dated between the 2nd century BCE to the 2nd century CE. Their safe provenance from the city and cemeteries of Roman Aquileia, and their number, offer an unparalleled statistical sample. Most of the objects belong to the natron-glass group. The families of HIMT glass and glass made from plant ashes are also represented. This compositional variety of glass supports the hypothesis that Aquileia was an important glass working center in the Roman age.

Towards a sharpest interpretation of analytical results by assessing the uncertainty of PIXE/RBS data at the AGLAE facility

The advances in object analysis and data processing are a real asset in science and in particular in the cultural heritage field. However, results interpretations depend on the reliability of the information obtained on the archaeological material studied. At the AGLAE facility, a specific methodology using the theory of analysis of variance (ANOVA) was followed in order to calculate the uncertainty of the PIXE and the RBS analyses due to the machine and to the data processing. Repeatability and reproducibility of measurements are studied on three PIXE standards and one RBS standard and the corresponding uncertainties are developed. Then results of RBS analyses on cultural heritage objects are presented to illustrate the discussion.

Non-invasive quantitative micro-PIXE–RBS/EBS/EBS imaging reveals the lost polychromy and gilding of the Neo-Assyrian ivories from the Louvre collection

Antique objects are known to have been brightly colored. However, the appearance of these objects has changed over time and paint traces are rarely preserved. The surface of ivory objects (8th century B.C., Syria) from the Louvre museum collection (Paris) have been non-invasively studied by simultaneous particle-induced X-ray emission (PIXE) and Rutherford and elastic backscattering spectrometry (RBS/EBS) micro-imaging at the AGLAE facility (C2RMF, Paris). Qualitative 2D chemical images of elements ranging from Na to Pb on the surface of the ancient ivory carvings provide evidence of lost polychromy and gilding. Quantitative PIXE data of specific areas allow discrimination between traces of sediments and former polychromy. Different shades of blue can be differentiated from particular Pb/Cu ratios. The characterization of gilding based on RBS data demonstrates the exceptional technological skills of the Phoenician craftsmen supposed to have carved the Arslan Tash ivories. More precise reconstructions of the original polychromy compared to previous studies and a criterion for the authentication of ancient gilded ivory object are proposed.

A new light on a first example of lustred majolica in Italy

A study has been realised to elucidate the first step of lustre production in Italy. With this aim in mind, an investigation was carried out on an emblematic lustred object: Baglioni’s albarello. It is conserved at Louvre museum and it is considered as one of the very first examples of lustred object produced in Italy. The characteristics of the lustred film have been determined, identifying interesting aspects that may be used to scientifically confirm the origin of this object. This study was completed by the investigation of other objects: a not lustred albarello, still decorated with the coat of arms of Baglioni’s family and a lustred plate with the coat of arms of the Montefeltro family. The two Baglioni’s albarelli are stylistically and historically considered as produced in one of the numerous workshops of Deruta. The origin of the Montefeltro’s plate, although from central Italy, is not precisely attested. In order to acquire more information, clarifying the origin and place of production of these objects, a comparison of their physico-chemical characteristics with results obtained and already published on different well-attested productions, such as Islamic, Hispano-Moresque and Italian, was carried out. For what concerns the museum objects, the use of non-destructive investigation techniques was mandatory. For this reason, ion beam techniques as PIXE and RBS have been used at AGLAE facility, as well as a new X-ray micro-diffraction equipment, at C2RMF. Moreover, the results were compared with data obtained on shards of certain production origin, by means of chemometric techniques. Some hypothesis concerning the place of production of the examined objects have been formulated.

PIXE analysis on Maya blue in Prehispanic and colonial mural paintings

Particle induced X-ray emission (PIXE) experiments have been carried out at the AGLAE facility (Paris) on several mural samples containing Maya blue from different Prehispanic archaeological sites (Cacaxtla, El Tajín, Tamuin, Santa Cecilia Acatitlán) and from several colonial convents in the Mexican plateau (Jiutepec, Totimehuacán, Tezontepec and Cuauhtinchán). The analysis of the concentration of several elements permitted to extract some information on the technique used for painting the mural, usually fresco. Principal component analysis permitted to classify the samples into groups. This grouping is discussed in relation to geographic and historic data.

An external milli-beam for archaeometric applications on the AGLAE IBA facility of the Louvre museum

External beam lines have been built on numerous IBA facilities for the analysis of works of art to avoid sampling and vacuum potentially detrimental to the integrity of such precious objects. On the other hand, growing interest lies on microprobe systems which provide a high lateral resolution but which usually work under vacuum. Until recently, the AGLAE facility was equipped with separate external beam and microprobe lines. The need of a better spatial resolution in the external beam mode has led us to combine them into a single system which exhibits numerous advantages and allows the analysis of small heterogeneities like inclusions in gemstones or tiny components of composite samples. The triplet of quadrupole lenses bought from Oxford is used to focus the beam. By using a 0.75 μm thick Al foil as the exit window, blowing a helium flow around the beam spot and reducing the window-sample distance below 3 mm, a beam size of about 30 μm can be reached. The experimental setup includes two Si(Li), a HPGe and a Si surface barrier detectors for the simultaneous implementation of PIXE, NRA and RBS. The full description of this device is given as well as a few applications to highlight its capability.