These studies were focused on the relation between the orientation of crystallites, calcium concentrations and the stress distributions within human vertebral bodies. The elemental composition was measured using the proton induced X-ray emission method in combination with a proton microprobe (micro-PIXE) while the orientation of the hydroxyapatite crystals was extracted from the X-ray diffraction spectra acquired during the synchrotron microprobe irradiation (micro-XRD). To calculate the distribution of stresses the finite element (FE) method was applied. The distributions of Ca concentrations indicate that the irradiated samples differ slightly in the degree of mineralization. The micro-XRD data confirmed that c-axes of the hydroxyapatite crystallites are preferentially oriented ((40–80)% of the crystals are textured). The comparison of the micro-XRD data and the results of the FE calculations proved the hypothesis that the preferential orientation of crystals reflects the mechanical loading of the structure.

Last progresses in synchrotron radiation focusing allow the characterisation on microscopic samples. The use of X Ray micro diffraction (muXRD) in two corrosion studies (indoor atmospheric corrosion and in soil corrosion) concerning iron archaeological artefacts is presented. This analytical method permits to locate and identify very precisely the constitutive phases of the corrosion products. For the atmospheric corrosion study, semi quantitative data were presented to assess the proportion of the different identified phases in the rust layers. For the in soil corrosion study, the precise distribution of corrosion products formed on the nine analysed artefacts is given.

At Echassieres (Allier, France), arsenic speciation was determined in a soil developed over a micaschist where Hercynian hydrothermal mineralization, including arsenopyrite FeAsS and lollingite FeAs2, has lead to a regional As anomaly. The overlying soils which have developed from long term weathering exhibit As levels as high as 900 ppm in the richest area, where the saprolite contains up to 5200 ppm As. Analysis by powder XRD, [nu]-X-ray diffraction on the 20[nu]m scale, SEM-EDS and electron micro-probe analyses revealed that As, released from arsenopyrite and/or lollingite alteration, is concentrated in a secondary iron arsenate, pharmacosiderite, (Bax,K2-2x) (Fe,Al)4 (AsO4)3 (OH)5 · 6H2O. Quantitative mineralogical analysis by Rietveld refinement indicates that the proportion of As hosted by this mineral decreases systematically from the saprolite to the topsoil (from 70 % to 30 % of the total bulk As content, respectively). EXAFS spectroscopy indicates that the main form of the As occurring with pharmacosiderite, consists of As(V) ions sorbed on iron oxides. Sorption processes, which dominate As speciation in the topsoil horizons, appear as a key mechanism able to delay As dissemination from soils to plant and surface waters, provided that pH and Eh conditions remain sufficiently acidic and oxidizing, respectively.

. The investigation of the interesting collection of the petrified wood from Bondyrz, Roztocze, south-eastern Poland, has been continued. Two kinds of microprobes such as electron microprobe from the Catholic University of Lublin and synchrotron-based X-ray microprobe from LURE, Orsay, were applied to detect the elements associated with the main component – silica and their spatial distribution and interrelations. The distribution of carbon in the petrified material has been established, which is important since that element is the main remains from the history of the trees. The carbon distribution was characteristic – it concentrated on a place of primordial dark wood. The distribution patterns of the other elements were either similar to that of carbon (Cu, Pb) or they concentrated in separate inclusions (Fe, Al, K, Na, Ca). The replicating mode of the original wood pattern in silica and carbon-containing material was explained. Some indications about the composition of the primordial petrifying solution, the rate of the petrifaction process and the recent coloration of the sample could be concluded from the compositional patterns of silica. The boundary between totally and partially petrified zones could be well observed.

Lead speciation was determined in a soil developed on a geochemical anomaly arising from a Pb-Zn stratabound deposit in Largentiere (Ardeche, France). This geological setting offers the opportunity to determine the preferred form(s) of Pb following soil formation on this unique anomaly. In the soil profile studied, Pb concentrates in the B-horizon (2055 mg/kg Pb) relative to both the A- (1330 mg/kg Pb) and C- (1874 mg/kg Pb) horizons. Plumbogummite (PbAl3(PO4)(2)(OH)(5).H2O) is the main host of Pb in the soil profile. Pb also appears to be associated with Mn-(hydr)oxides, as shown by micro-analyses (EMPA, SEM-EDS, and mu -SXRF),in the form of inner-sphere Pb2+ complexes, as suggested by Ph L-HI-edge EXAFS spectroscopy. Linear least-squares fitting of background-subtracted, k(3)-weighted Pb L-III-edge EXAFS functions derived from balk soil samples was carried out using Ph L-III-EXAFS spectra of 22 Pb-containing model compounds. Quantitative assessment of Pb speciation revealed that, whereas plumbogummite is the most abundant Pb phase in the soil profile, Pb2+-Mn-(hydr)oxide surface complexes are gradually replaced by Pb2+-surface complexes with other phases, possibly Pb2+-organic complexes, upward in the soil profile. The presence of large amounts of Pb-phosphate in the Largentiere soil suggests that low solubility phosphates may be important long-term hosts of Pb in Pb-contaminated soils that have sufficiently high phosphorous activities to cause formation of these phases.

Synchrotron microprobe and X-ray fluorescence spectrometry (XRFS) were used to analyse several teeth and pieces of bone, respectively, originating from subjects of the chalcolithic period. A synchrotron microprobe with 100 μm resolution and monochromatic photons of 18 keV were used to scan teeth from the root to the enamel. Bones were analysed by XRFS for their amount of trace elements, using a spectrometer based on a three-axial geometry and an incident beam of 17.4 keV. The detected elements for both analytical procedures were P, K, Ca, Mn, Fe, Cu, Zn, Br, Sr and Pb. The results show high concentrations of Mn, Fe and Cu for different tooth regions when compared with data from contemporary subjects. Moreover, the high levels of Br and Sr can be associated with environment influence and dietary habits rich in protein, especially seafood. It is remarkable that lead is always of the order of magnitude of the detection limit, which is 1–2 μg/g in all analysed teeth. Furthermore, the microprobe analysis of these samples showed that the highest concentration of the heavy metals increases from the outer enamel to the inner dentine root. For the analysed bone samples of women and men, the most important aspects concerning the elemental concentrations are the high levels of Mn and Br and the low concentrations of Pb, as found for teeth.

Pieces of petrified wood from south-eastern Poland comprising one of the greatest European collections were investigated. The age of Miocene wood was estimated at 50 million years. Taxodioxylon sequoianum Gothan. was recognised as the dominating species among the preserved samples. Silica material, basic for the petrifaction processes, was investigated by synchrotron-based microfluorescence and microdiffraction. Different distribution patterns were determined after careful examination of linear scans and elemental maps: calcium, potassium and titanium were uniformly spread in the silica matrix while the iron content was concentrated in clear inclusions; other detected elements, as Cu, Zn, Cr, As were observed mainly in the form of inclusions. There was no difference in microdiffractograms for silica between the places of original dark and light wood. One could find little difference in diffraction patterns of samples with the elevated content of iron. In general, the diffraction patterns of silica from petrified wood could be associated with quartz patterns from 1998 JCPDS-International Centre for Diffraction Data.

The chemical composition and crystalline nature of inorganic deposits present in the human aortic wall were investigated. A proton microprobe in combination with proton induced X-ray emission and proton induced gamma-ray emission were used to determine quantitatively the elemental composition of the inorganic deposits while their structure was studied with the use of an X-ray microprobe in combination with X-ray diffraction and Fourier transform infrared microscopy.It was found that deposits in the aortic wall are composed of Ca-P compounds. Fluorine is accumulated in the inorganic phase. However, the mechanism of F deposition awaits further investigations. The only phase detected by the X-ray diffraction was a defective hydroxyapatite. The relative intensities of reflexes indicate that the c axis of the crystallites is parallel to the long axis of the vessel. IR microscopy revealed that the crystals were contaminated with carbonate groups. Moreover, the band characteristic for octacalcium phosphate was detected. (C) 2000 Elsevier Science B.V. All rights reserved.

The use of liquid scintillation counting as a fundamental radionuclide standardisation method requires a correct description of the physical phenomena induced by the interaction of the ionising radiation with the liquid scintillator. In particular the standardisation of radionuclides decaying by electron capture as 55Fe and other electron-capture nuclides, requires the knowledge of total linear absorption coefficients of the liquid scintillator used for absolute activity measurement. Total linear absorption coefficient measurements have been undertaken using synchrotron radiation. Linear absorption coefficients of two widely used commercial liquid scintillators were measured in the 5.5-23 keV energy range. Small discrepancies were noted between theoretical and measured values of the Ultima-Gold mass attenuation coefficients for low energy photons.

Samples of petrified wood of different origins were analyzed by the use of the electron microprobe, capillary X-ray fluorescence microprobe, synchrotron capillary X-ray microprobe and optical microscope, applied in a microprobe manner. The main attention was given to the investigation of the ring structure of the petrified wood and the comparison of this with the ring structure of the living trees analyzed by much the same methods. The continuous X-radiation, applied in a microprobe manner, the distribution of the gray-scale representation of the secondary electron intensities and the characteristic X-ray signals, mainly from the light elements, were registered by the use of the electron microprobe method. The X-ray capillary microprobe detected the Rayleigh and Compton signals, scattered from microareas of the samples, and the characteristic X-ray signals, mainly from the heavier elements. In the synchrotron-based capillary microanalytical measurements, one of the most important results was achieved by the microprobe application of scattered synchrotron radiation. The emission and scattering results were supplemented by transmission measurements, where possible. All the methods proved to be complementary in the analysis of such periodic structures as tree rings. Both capillary microprobes were much more efficient in the detection of heavy elements and penetrated deeper than the traditional electron microprobe. Careful analysis of different signals indicated that some samples of petrified wood in the authors' possession, composed of silica of variable density, are the chemical negatives of the primordial living wood. This is the first such observation in the literature. Microdiffraction studies of the samples proved that polycrystalline α-quartz was the main matrix component of all these samples. The elemental analysis of the petrified wood gives important indications about the petrification processes. Comparison of the particular ring structure of the petrified wood with the ring structure of living trees shows great similarities. The widths of rings, density variations and density maxima are easily readable from the microanalysis of petrified wood. These parameters potentially can be exploited for the investigation of the biological, chemical, chronological and climatic information included in the fossilized tissues.

Chemical forms of lead were determined and quantified in a naturally enriched soil (1330 - 2055 mg/kg Pb) developed on a geochemical anomaly. XRD and EXAFS data evidence that plumbogummite (PbAl3(PO4)(2)(OH)(5).H2O), a low solubility mineral (K-s = 10(-29.4)), is the main lead phase along the soil profile investigated. Lead is also present as inner-sphere Pb(II) complex sorbed onto manganese (hydr)oxides and onto soil organic matter. Variations of the relative proportions of these forms of lead along the profile studied indicate that i) the proportion of plumbogummite is almost constant ii) Pb(II)-manganese (hydr)oxides complexes are gradually replaced by Pb(II)-organic matter complexes upward the soil profile. Besides, geochemical balance based on Zr invariant suggests a global loss of lead during soil formation.

The various techniques used to produce X-ray microbeams in a synchrotron facility and a few examples of applications are presented. The use of microbeams with techniques like diffraction, EXAFS and XANES presents a great interest for the future development of photon microprobes.

An X-ray fluorescence set-up with microprobe capabilities, installed at the Laboratoire pour l’Utilisation du Rayonnement Électromagnétique (LURE) synchrotron (France) was used for elemental determination in teeth. To evaluate the influence of living habits in dental elemental composition nine teeth collected post-mortem were analysed, five from a miner and four from a fisherman. All teeth from the fisherman were healthy. From the miner some teeth were carious and one of them was filled with metallic amalgam. Teeth were sliced under the vertical plane and each slice was scanned from the root to the enamel for elemental profile determination. The synchrotron microprobe resolution was of 100 μm and incident photons of 18 keV energy were used. The elemental concentration values found suggest heterogeneity of the teeth material. Moreover, the distinct profiles for Mn, Sr, Br and Pb were found when teeth from the miner and from the fisherman are compared which can be associated with dietary habits and environmental influence. Higher concentrations of Mn and Sr were found for the fisherman teeth. In addition, Br was only observed in this group of teeth. Pb levels are higher for the miner teeth in particular for dentine regions. The influence of amalgam, such as, increase of Zn and Hg contents in the teeth material, is only noticed for the immediate surroundings of the treated cavity.

The use of ion beam techniques applied to teeth studies have been extensive in what concerns the major elements distribution. However, it is not clarified whether amalgam components are absorbed and drifted through teeth material, although the toxicity of the elements used in amalgams, such as Hg, are well known. This work is an attempt to assess a possible teeth contamination originated by the amalgams. Therefore, teeth with metallic amalgam, as well as healthy ones, were studied. The teeth were longitudinally cut and each slice was scanned from the inner region to the surface enamel for elemental profiles determination purposes using Particle Induced X-ray Emission (PIXE) and Synchrotron Radiation X-ray Fluorescence (SRXRF) techniques. High levels of Zn, Ag, Sn, Hg and Pb were found along the scanned teeth restored with the metallic amalgam. The elemental distribution patterns suggest diffusion of these elements in the teeth material from amalgam constituents.

The main limiting factor associated with individual fluid inclusion analysis using synchrotron radiation X-ray fluorescence (SRXRF) is the quantification of absorption of the incident and fluorescent radiation by the fluid and the host material. Theoretically, the measured (Kα/Kβ)z intensity ratio from a given element Z in solution is directly proportional to the thickness of material traversed and therefore could be used as a reliable term for the absorption correction. In order to constrain experimentally the relationship between (Kα/Kβ)z, host material thickness and fluid inclusion size and salinity, a three-step protocol has been developed using the LURE (Orsay, France) photon microprobe installed on line D15. These are: (1) interception of the X-ray fluorescent beam emerging from pure-metal targets (Mn, Fe, Ni, Cu, Zn) using thin plates of aluminium and quartz of known thicknesses; (2) feasibility tests on silica-glass capillaries containing known concentrations (∼5000 ppm) of various metals (Mn, Ni, Zn) and salts (0 and 15 wt.% NaCl); (3) confirmation tests on synthetic fluid inclusions containing known metal contents (∼1000 ppm Ni and Zn) hosted in halite crystals. The results of experiment 1 indicate that the evolution of the (Kα/Kβ)z ratio as a function of host material thickness is in perfect agreement with theoretical predictions and is independent of the local analytical environment (reproducibility of the measurements). For experiments 2 and 3, the (Kα/Kβ)z ratio of a reference element in solution (Zn), was used to estimate the thickness of host material traversed. Establishing that the X-ray peak intensity of Zn corresponds to a given concentration allowed the concentration of other trace metals in solution to be determined. In both experiments, the precision is high with standard deviations (1σ) from 1 to 8% of the mean, but the accuracy can be relatively poor with mean values ranging from 3–11% (capillary tests) to as high as 17% (inclusion tests) of the known concentrations. Tight ranges of calculated metal concentrations at values higher than the known concentrations strongly suggests that the Zn concentration used to calibrate the Zn X-ray peaks may be different from that effectively measured using SRXRF. A knowledge of Mn, Ni and Zn chloride and silica speciation during SRXRF measurements is required to evaluate better this potential source of error. Despite this, results are commonly better than 20% (experiment 2) and 32% (experiment 3) relative to the known concentrations. This implies that elemental concentrations in individual fluid inclusions can be quantitatively determined using the SXRF technique without precise knowledge of the inclusion depth and geometry.

The advent of synchrotron radiation and the enormous development of X-ray optics made it possible the realization of photon microprobes. Micrometer size hard X-ray beams can be obtained through various arrangement and the flux is intense enough to undertake elemental mapping of trace elements. Associated with microdiffraction or with X-ray Absorption Near Edge Structure, these microprobes will become a very interesting tool for material characterization.

A proton microprobe in combination with proton induced X-ray emission and a X-ray microprobe are used in the study of the mineralization process. It is demonstrated that the application of both methods enables the determination of the crystallographic structure of the inorganic phase in biological samples with a spatial resolution of about 20 μm.

The spectra and decay time of RbCaF3 emission at monochromatic X-ray excitation have been measured. It is shown that the short wavelength fast (2.8 ns) intrinsic luminescence of the crystal consists of two bands (245 and 285 nm), which confirms the model of radiative core-to-valence transitions for perovskite structure crystals. A stepwise decrease of the light yield near the K-edge adsorption of Rb (15.2 keV) is observed.

We present experimental data on a novel type of optical element for synchrotron radiation applications in the X-ray region: namely a straight glass capillary array. The spectral reflectance and transmittance for two capillary samples with length of 10 mm and 19 mm have been measured in the photon energy range from 7 to 30 keV using synchrotron radiation from the DCI storage ring at LURE, Orsay. High reflectance (up to 50%) and good energy-filtering properties were obtained. This opens up the possibility to use a capillary array as an effective beam-splitter and as a high-energy filter in synchrotron radiation beamlines.

Decay kinetics of 4f25d state of Nd3+ is very fast (τ ~ 1 ns) in NdF3 where concentration quenching of Nd3+ emission is observed. It is near-exponential in YF3-Nd, where relatively weak quenching of emission takes place at high-energy excitation. It shows distinct rise time in LiYF4-Nd where the delayed energy transfer to emission centers is observed. The latter starts at excitation energies higher than the energy of intrinsic absorption edge of the matrix and disappears at low temperature. The model for the mechanism of the delayed energy transfer in LiYF4-Nd is proposed.