Emmanuel Pantos

Science and Technology Facilities Council | STFC · Scientific Computing Department

The luminescence properties of Fe3+ defects in feldspar are well know, but the role played by Fe2+ centres remains ambiguous, with tentative previous evidence suggesting it could act as a luminescence activator, luminescence quencher, or neither one nor the other: the outcome of these arguments would be of direct and topical relevance to considerat...

A wooden shovel, dating from the Early Bronze Age, has survived in a remarkable state of preservation in the copper mines of Alderley Edge, Cheshire UK. Other historic timbers recovered from the mines, whilst still intact, have fared less well. An X-ray investigation into the distribution of minerals through the shovel using portable X-ray Fluoresc...

A 19thcentury box of unused watercolour pigment cakes, manufactured by Winsor and Newton and currently at the Victoria and Albert Museum, was analysed using several techniques. The box and its contents are in remarkably good condition, with most of the watercolour cakes being still intact; thus a unique opportunity was made available to study unadu...

The object of this study is a battle helmet of Corinthian type, now in the collections of The Manchester Museum. The Corinthian helmet has been called “sone of the great independent achievements of early Greek technology”. It was manufactured out of a single piece of bronze, probably on a rod-anvil, and like all body-armour it was made to measure....

Crystalline phases present in pigments scratched off the surfaces of some decorated ceramic sherds belonging to the Cucuteni Neolithic culture were successfully identified using synchrotron radiation X-ray diffraction at Daresbury Laboratory. The ceramic sherds were selected from a collection of the National Museum of Romanian History in Bucharest....

Ancient documentation referring to the use of cinnabar in the production of luster decorations has recently been corroborated by archaeological findings. However, luster decorations do not show any trace of the use of cinnabar in their composition because the temperatures involved in luster firing (500°–600°C) result in the complete decomposition a...

The phase transformations as a function of the temperature of two natural illitic clays were investigated through XRD measurements, ex situ at room temperature with conventional set up and in situ with synchrotron radiation, in order to understand the origin of the corundum phase, which is one of the main characteristics of the red glaze (slip) of...

A thirteenth-century sacred and profane wall painting has been rediscovered during renovation work in a city castle in Krems, Lower Austria. A frieze with alternating blue circles and green diamonds attracted attention to the unusual green colour. Several analyses by means of light microscopy, scanning electron microscopy - energy-dispersive X-ray...

In this work, the potentiality of two-dimensional X-ray diffraction (XRD(2)) to characterise aerosol particles collected on commercial glass filters is presented. Indeed, even if routine analysis usually requires only mass determination, and rarely chemical composition, phase determination is fundamental to recognize the primary or secondary origin...

Luster is a golden metallic-like decoration produced on glazed ceramics since early Islamic times (Iraq, 9th AD). Luster is obtained by the reaction of a luster paint and the glaze surface over which it is applied. A temperature-resolved XRD experiment was designed to study the high temperature reactions in the luster paint while the luster layer i...

How familiar were the pre-Homeric Greeks with Egyptian technology? Accounts of apparent mythological nature and archaeological evidence indicate cultural contacts. To what extent did Greek craftsmen learn their art from Egyptians? At excavations in Djoser's pyramid (3rd dynasty, ca. 2750 BC) some 36000 glazed tiles were found, most with a turqoise-...

The high analytical sensitivity and high spatial resolution of synchrotron radiation-based techniques, in particular SR-XRD and SR-FT-IR, allows the identification of complex micrometric mixtures of compounds that constitute the different layers of ancient paintings. The reliability of the measurements even with an extremely small amount of sampled...

With the aim of contributing to the knowledge of north-Mesopotamian Bronze Age pottery production (3rd millennium BC, early Dynastic and early Akkadian period), the mineralogy of pottery excavated from the site of Tell Beydar (Syria) has been studied in order to make inferences concerning the clay preparation and firing techniques of that period. T...

The North Western Iberia metal ore wealth, especially tin ore and gold, have been proposed as the main reason for the development of intense trade routes since early prehistory. Several authors have argued the existence of interactions between the northwest of the Iberian Peninsula and other cultures of the European Occident and theMediterranean ar...

The object of this study is a battle helmet of Corinthian type, now in the collections of The Manchester Museum. The Corinthian helmet has been called “one of the great independent achievements of early Greek technology”. It was manufactured out of a single piece of bronze, probably on a rod-anvil, and like all body-armour it was made to measure. T...

How familiar were the pre-Homeric Greeks with Egyptian technology? Accounts of apparent mythological nature and archaeological evidence indicate cultural contacts. To what extent did Greek craftsmen learn their art from Egyptians? At excavations in Djoser’s pyramid (3rd dynasty, ca. 2750 BC) some 36000 glazed tiles were found, most with a turqoise-...

Archaeological cellulose textile fibres (linen and cotton) from caves in the Dead Sea region were investigated using synchrotron X-ray microdiffraction. The degradation of the up to 2100year old fibres was found to depend on the climatic conditions at the place of storage. The size and the lattice parameters of the cellulose nanocrystals (microfibr...

Two analytical methods - 241Am-based X-Ray Fluorescence (XRF) and Synchrotron Ra- diation X-ray Diffraction (SR-XRD) - were used to investigate the elemental and mineralogical com- position of pigments which decorate some Cucuteni Neolithic ceramic sherds. Local hematite and lo- cal calcite were the main components for red and white pigments, respe...

From ancient times to today glasses, generally based on siliceous oxides cooled to a hard condition to avoid crystallization, have been extensively used, for their chemical-physical durability. Indeed, glass is one of the materials most frequently discovered during archaeological excavations. The degradation induces the loss of brightness and trans...

sTwo non-destructive neutron techniques have been used for the analysis of archaeological objects, among them English monumental brass plates, Dutch tin-lead spoons, a Roman leaded bronze fibula and several limestone samples. Prompt Gamma Activation Analysis (PGAA) is a non-destructive method for determination of the major and trace element composi...

In the early 9th century AD ancient potters of Iraq discovered that after firing some copper oxides and silver salts with clay, iron oxides and some sulphur compounds applied on a ceramic glaze produced a beautiful layer with a wide range of colours, from reddish to yellowish or even greenish, and some with a characteristic metallic copper or purpl...

Microprobe EXAFS analysis of lustre decoration from a late 13th century Hispano-Moresque potsherd has been used to examine the metallic oxide to metal ratios in different shaded copper lustre finishes. A single specimen from 13th century Paterna, exhibiting typical red and green colorations, is found to contain different copper/silver ratios depend...

Neutron radiation offers several advantages with respect to traditional archaeometric analyses of art objects and of archaeological materials, largely derived from its high penetration through matter. Neutrons penetrate coatings and thick corrosion layers and reach into the bulk of a material without substantial attenuation, a property that makes t...

This research is aimed at assessing the particular kind of damage caused by the interaction between atmospheric pollution and the marble surface of a magnificent late gothic church, Milan Cathedral, restored in the early 1970s. On the basis of visual inspections and diagnostic investigations the facade appears to be seriously damaged by surface ero...

Single 2000-year-old archaeological fibres from textile fragments excavated in the Cave of Letters in the Dead Sea region were investigated by a combined approach using microscopy (optical and SEM), X-ray microbeam diffraction and X-ray microbeam fluorescence. In comparison with modern reference samples, most of the fibres were identified as wool,...

Ten archaeological Punic make-up samples from Tunisia dating from the 4th to the 1st centuries BC were analysed by several techniques including Raman microscopy and synchrotron X-ray diffraction in order to determine their compositions. Eight samples were red and found to contain either quartz and cinnabar or quartz and haematite. The remaining two...

The information that can be retrieved from the study of ancient materials and studies on their conservation rely strongly on the development and application of new techniques of physical analysis. This is particularly important at a time when global changes affecting our environment and way of life impose new stresses putting heritage preservation...

With the aim of shedding new light on the still poorly understood North Mesopotamian metallic ware, ceramic and soil samples from Tell Beydar (northeastern Syria, third millenniumbc) were investigated using a range of analytical techniques, including optical microscopy, SR–XRD and SEM–EDX. The objective of this work was to differentiate calcareous...

A new method of ion-exchange between raw compounds containing copper oxide and alkali glasses has been used to grow copper nanoparticles within a glass matrix, forming a metal-glass nanocomposite that is the structure on which both ancient and modem lustre glazes are based. When excited by X-rays at 300 K, two dominant emission bands appear in the...

The focus of this study consists of examining how corrosion potential measurements can contribute in providing information on the effectiveness of storage and stabilization treatments of copper alloys in aqueous solutions. We report on the electrochemical behavior of artificial copper alloy coupons (covered or not with corrosion layers), simulating...

It has recently been shown that lustre decoration of medieval and Renaissance pottery consists of silver and copper nanoparticles dispersed in the glassy matrix of the ceramic glaze. Here the findings of an X-ray absorption fine structure (XAFS) study on lustred glazes of shards belonging to 10th and 13rd century pottery from the National Museum of...

Feasibility studies have been carried out at the Daresbury Laboratory Synchrotron Radiation Source, the SRS, with the aim of demonstrating the advantages, and evaluating the effectiveness, of synchrotron radiation over conventional methods in the context of Archaeological Science. The combination of X-ray diffraction, X-ray fluorescence and small/w...

The famous Dead Sea scrolls, found in 1947 at Qumran, point to a group of people, the “Essenes”, described by Pliny, Flavius Josephus and Philo. A large number, recently estimated to be around 950 biblical, sectarian and apocryphal manuscripts have been associated with the Essenes. In 1998, interdisciplinary laboratory research started in Jerusalem...

Single 2000-year-old archaeological fibres from textile fragments excavated in the caves of Qumran in the Dead Sea region were investigated by a combined approach using microscopy (optical and SEM), X-ray microbeam diffraction to determine the structure and X-ray microbeam fluorescence in order to identify trace elements. In comparison with modern...

The focus of this study consists of examining how simultaneous SR-XRD and electrochemical measurements can provide information on the effectiveness of stabilization and storage treatments of copper artefacts in aqueous solution. The electrochemical cell used here was designed for in situ, time resolved SR-XRD studies of corrosion and inhibition stu...

Neutron and synchrotron X-ray diffraction, X-ray fluorescence and FTIR were used to examine a Corinthian-type bronze helmet which is now on display at The Manchester Museum, UK. This type of helmet was manufactured out of a single piece of bronze, probably on a rod-anvil, and like all body-armour it was made to measure. Neutron diffraction sampling...

Synchrotron radiation Fourier transform infrared (SR-FT-IR) microspectroscopy represents an advance over conventional FT-IR spectroscopy because it gives a higher signal/noise ratio at the highest spatial resolution due to the high brightness and collimation of synchrotron radiation. It has been successfully applied to the study of ancient painting...

Analysis of medieval luster ceramics seems to indicate that the formation of luster layers could involve an ion exchange between some alkali ions of the glaze (Na+ and K+), and copper and silver cations of the luster raw paint during firing. However, because of the weathering shown by the medieval luster decorations analyzed, conclusive proof is di...

Wavelength-resolved optically-detected X-ray absorption experiments are described that monitor the emission from naturally occurring phase-exsolved aluminosilicate feldspars, when exciting across the Ca and K L2,3 core levels. The results from a selection of example cases are presented that demonstrate the power of the technique in examining the st...

Within the framework of a technological and socio-economical study of pottery production in Tell Beydar (NE-Syria) during the third millennium BC, the chemical composition and mineralogy of cooking pottery from that site has been studied using polarizing microscopy, scanning electron microscopy with energy dispersive X-ray detection (SEM-EDX) and X...

Archaeological textiles fragments from the caves of Qumran in the Dead Sea region were investigated by means of X-ray microbeam diffraction on single fibres. This non-destructive technique made the identification of the used plant textile fibres possible. Apart from bast fibres (mainly flax), cotton was identified which was most unexpected in the a...

The design use and implementation of simple but highly efficient instrumentation is described, that allows for the possibility of wavelength-resolving optically detected X-ray absorption spectra (OD-XAS) of even the weakest luminescent systems emitting in the range 380–1020 nm (1.2–3.3 eV). The instrument, based on linearly-variable interference fi...

Ancient documentation referring to the use of cinnabar in the production of luster decorations has recently been corroborated by archaeological findings. However, luster decorations do not show any trace of the use of cinnabar in their composition because the temperatures involved in luster firing (500degrees-600degreesC) result in the complete dec...

The present study aims to understand the reasons for the visual differences of black gloss pottery found in northern Etruria. The results obtained by conventional (scanning electron microscope, electron microprobe) and synchrotron (X-ray diffraction, X-ray absorption spectroscopy) techniques indicate that the thickness, porosity or chemical composi...

__________________________________________________________________________________________ Abstract Archaeological copper artefacts recovered from wet saline environments are often stored in tap water and stabilized in sodium sesquicarbonate solutions. Modification of the natural patina and development of active corrosion can occur during these pro...

A new mobile end-station is described for use on multiple beamlines at the Daresbury synchrotron radiation source (overall excitation range 5 eV to 70 keV) that allows for the detection and dispersion of photoluminescence from solid-state samples in the emission range 190-1000 nm (1.2-6.5 eV). The system is fully self-contained and includes sample-...

This paper describes the use of several microbeam analysis techniques for the chemical characterization of corrosion compounds on ancient bronze objects. They include optical microscopy, SEM-EDX, TOF-SIMS, SR-FTIR, SR-XRD, and XANES. The objective is to investigate which combination of analysis methods is most suitable for this type of application,...

We demonstrate that the visible/UV luminescence from common feldspar crystals (NaAlSi3O8, KAlSi3O8 and CaAl2Si2O8) can be used to detect detailed L-edge and associated near-edge absorption structure of the main constituent atoms (Ca, K, Na, Al, Si), when exciting in the energy range 20-500 eV. Comparisons of the spectral features are drawn with sim...

Lustreware is a traditional decorative finish applied to ceramics, giving a copper-gold metallic finish. Following an Islamic tradition, it was a highly prized luxury finish that was exported throughouthe Mediterranean in medieval times. The technology required to produce the highly desired artifacts was the province of highly skilled artisans, tha...

Examples are presented of the use of SR modalities for the molecular characterisation of archaeomaterials. They focus on the utilisation of the most basic of synchrotron radiation properties, high brilliance and energy range that can be selected. Two techniques have been employed, X-ray diffraction and X-ray absorption spectroscopy, to characterise...

The scientific investigation of ancient paintings gives a unique insight into ancient painting techniques and their evolution through time and geographic location. This study deals with the identification of the green pigments used by one of the most important Catalan masters in Gothic times, Jaume Huguet. Other pigments and materials have also bee...

We have studied the mineral composition of the gloss and the ceramic body of three pieces of Attic Greek pottery by applying the technique of high-resolution powder diffraction using synchroton X-rays. The measurements were performed on Stations 2·3 and 9·1 at the Synchrotron Radiation Source, Daresbury Laboratory. High quality powder patterns from...

Time-of-flight neutron and synchrotron X-ray diffraction were used for fingerprint determinations and quantitative mineral phase analyses of archaeological objects. Both neutron and X-ray diffraction techniques have their advantages and drawbacks when used in archaeological research. Neutron diffraction allows non-destructive analysis of complete a...

A genetic algorithm for iterative fitting of SAXS data is presented. The algorithm described produces fast convergence to a fittest model mass distribution compatible with experimental data. This method affords a dramatic reduction of processor time required by other SAXS fitting methods and can be applied to any kind of structure, the only require...

The gas-phase extinction-coefficient spectra of ten fluorosubstituted benzenes are presented and compared with benzene in the region 4.5-9.5 eV. The three singlet-singlet transitions analogous to the B2u from A1g, B1u from A1g and E1u from A1g transitions of benzene are presented and discussed. The appearance of the elusive 1E2g state is reported i...

Two new computer simulation programs are presented, GRASP and DALAI. GRASP is an off-lattice implementation of the cluster-cluster aggregation model, including diffusion and reaction-limited aggregation as well as aggregate reorganization. The aggregate systems produced by GRASP are characterized by DALAI, which calculates the X-ray scattering patt...

Small-angle x-ray solution scattering (SAXS) is analyzed with a new method to retrieve convergent model structures that fit the scattering profiles. An arbitrary hexagonal packing of several hundred beads containing the problem object is defined. Instead of attempting to compute the Debye formula for all of the possible mass distributions, a geneti...

X-ray small angle scattering measurements on silicate and berate glasses are described and the contrasting effects of inhomogeneities such as density fluctuations and alkali microsegregation are discussed. The consequences of microstructure for ionic diffusion, the mixed alkali effect (MAE), thermal expansion, glass fracture and polishing are consi...

Synchrotron radiation multiple diffraction in Renninger scanning (RS) geometry is used to characterise an Al0.304Ga0.172In0.524 As hetero-epitaxial layer MOVPE grown onto InP(001). (006) RS data for bulk, InP substrate and the quaternary layer were obtained using a new experimental set-up on station 7.6 at the Daresbury synchrotron radiation source...

During the preparation of silica by acidification of water glass, primary silica particles form extended and ramified aggregates. The growing aggregates form a gel, a tenuous network of interconnected aggregates. After aging and drying of the wet gel, porous silica is obtained. To study the extremely vulnerable aggregates only noninvasive methods a...

We describe a central processing unit (CPU)-efficient expansion of the Debye scattering formula for the calculation of small-angle scattering patterns of model systems composed of different types of scatterers. The algorithm permits the use of atomic scattering factors or form factors of hard spheres of variable radius and scattering density. We ap...

An experimental facility for carrying out x‐ray multiple diffraction (XRMD) studies in parallel‐beam geometry using the Daresbury synchrotron radiation source and its application in the study of coherency of an epilayered sample are described. Experimental high‐resolution Renninger scans (RS) about GaAs(006) are presented and the pseudoforbidden ‘‘...

The application limit of the MULTX program for predicting Renninger-scanning X-ray multiple diffraction data is extended in order to simulate Renninger scans for semiconductor single-crystal and heteroepitaxial structures recorded using synchrotron radiation. The experimental synchrotron-radiation Renninger scan for InP(006) bulk material is taken...

Porous silica gel has been prepared by acdification of water glass. To study aggregation, gelation andaging use has been made of 29Si-NMR to investigate silica transformations on molecular scale. Qn ratios were used to define distribution of silica in particles and gels. On colloidal scale both 1H relaxation of water and small angle scattering (SAX...

Aggregation and aging of silica gels, prepared by controlled addition of water glass to hydrochloric acid, and the transformation of an aged gel to a crystalline phase have been studied in-situ using high-brilliance synchrotron radiation.Small angle X-ray scattering (SAXS) has proved to be very informative in readily detecting transformations in th...

The scanning transmission X-ray microscope at the Daresbury Laboratory has been used to form direct high-resolution images of gels prepared from aged silica sols at different pH values. The pH plays an important role in the determination of both the gelation rate and the microstructures observed in the aggregates of the silica gel. The fractal dime...

Off‐lattice diffusion limited cluster aggregation simulations in two dimensions have been performed in a wide volume fraction range between 0.001 and 0.60. Starting from a system of 10 000 monomers with radius 0.5, that follow Brownian trajectories, larger aggregates are generated by bond formation between overlapping aggregates. No rings are prese...

Computing provision is of major concern to synchrotron radiation researchers. An overview is presented of the computing facilities for synchrotron radiation work at the Synchrotron Radiation Source, Daresbury Laboratory. Data acquisition, reduction and analysis are seen as an integrated activity essential for full utilization of beam time. We discu...

GDP liganded tubulin, which is inactive in microtubule assembly, polymerizes into rings more readily than the active GTP liganded protein. The structure of double rings made of highly purified GDP-tubulin has been characterized to 3 nm resolution with synchrotron X-ray solution scattering. The scattering profile has characteristic maxima due to clo...

Growth and aging of silica aggregates are influenced both by temperature and by catalyzing fluorine ions as shown by SAXS and BET. It was found that both fluorine and increased temperature slightly increased the fractal dimension Df during aging, but the fluorine catalyzed system showed a lower BET surface area. To understand the effect of fluorin...

We describe two algorithms used in structural studies of proteins and macromolecular complexes. The first deals with simulation of Small Angle X-ray Scattering patterns. An approximate representation of the Debye formula based on the discretized histogram of pair distances allows the SAXS calculation of large macromolecules modelled by thousands of...

Silica hydrogels show fractal properties corresponding with DLCAA or RLCCA. During aging silica is redistributed, resulting in reinforcement of the tenuous structure and only slightly disturbing fractal geometry. In zeolitic precursors no mass-fractals are present, but SAXS spectra show strong indications for the presence of surface-fractals. Compu...

Four computer algorithms of relevance to Synchrotron Radiation research have been implemented for parallel execution using the Parallel Virtual Machine (PVM) software harness. In all four cases the Single Program Multiple Data (SPMD) approach has been used resulting in a computationally simple but very effective implementation where processing time...

The structure of microtubules has been characterized to 3 nm resolution employing time-resolved X-ray scattering. This has revealed detailed structural features of microtubules not observed before in solution. The polymerization of highly purified tubulin, induced by the antitumour drug taxol, has been employed as a microtubule model system. This a...

X-ray solution scattering has been used for studying the structural changes that take place upon uptake and release of iron from serum and chicken ovo-transferrin and human lactoferrin. In the case of chicken ovo-transferrin, data have been obtained for both the intact protein and the isolated N and C-lobes with and without iron. These studies reve...

Since the early work of Huxley and collaborators [H. E. Huxley, A. R. Faruqui, J. Bordas, M. H. J. Koch, and J. R. Milch, Nature 284, 5752, 140 (1980)], time‐resolved x‐ray diffraction using synchrotron radiation has provided and continues to provide unique information on the structural dynamics of muscle, thus addressing the fundamental question o...

The X‐ray solution scattering profiles of taxol microtubules made of purified tubulin and control microtubules, assembled either from purified tubulin in glycerol buffer (a non‐specific enhancer of the polymerization of tubulin) or from microtubule protein (a preparation containing tubulin plus microtubule associated proteins), were obtained to 3.3...

Microtubules are important components of the cytoskeleton in eukaryotic cells. In-vitro assembled microtubules have been observed by cryo-electron microscopy of frozen-hydrated samples. The individual microtubules can be easily characterised in terms of the number of their constituant protofilaments by direct examination of their image contrast. Th...

A versatile instrument for glancing‐angle x‐ray absorption spectroscopy (XAS) and x‐ray reflectivity in routine use on the Daresbury Synchrotron Radiation Source is described. This facility can be used for XAS measurements in both reflectivity and fluorescence modes as well as for qualitative studies of angular dependent x‐ray reflectivity. Reflect...

Multiple diffraction using parallel-beam synchrotron X-radiation is described. Data recorded on the Daresbury Synchrotron Radiation Source from a single-crystal of InSb are presented and compared with data recorded with the pseudo-Kossel technique. The wide-beam synchrotron technique has demonstrated for the first time the feasibility of the synchr...

Absolute extinction coefficient and oscillator strength of pyridine, pyrimidine, pyrazine, and s-triazine were recorded with moderate resolution in the region of 3.5–9.5 eV. Analogous to , 1B1u, transitions of benzene, several n → π∗ and Rydberg transitions are presented and discussed.

Contrast near an absorption edge has been observed in synchrotron radiation topographs obtained with white radiation due to the variation of wavelength across an image. Variations in absorption, due to the fluctuations in the EXAFS spectrum, appear as fringes parallel to the edge. The contrast has been measured densitometrically for a Nb specimen a...

The theory of optimal filtering and smoothing of noisy data is presented. Implementation of this theory is made on the AS/7000 computer at Daresbury Laboratory. The Fortran code and examples of application on 'typical' spectroscopic data are given. The routine size is 35 kbytes and the CPU time 0.11 s for 1024 points.

The suite of programs descibed here have largely evolved from a ray-tracing procedure which makes explicit use of a vector form of Snell's law for reflection and diffraction [1]. Any number of elements may be raytraced (slits, mirrors, classical or holographic gratings) that may be coplanar or orthogonal to each in any configuration. The surface ma...

The SRS program library consists of a collection of programs and other utilities to support data reduction and analysis by users of the Synchrotron Radiation Source at the Daresbury Laboratory. It covers four main areas of programmed facilities, file manipulation and programming aids, general spectroscopic data reduction, specialised packages for S...