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.

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.

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.

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.

In creating an X-ray superprobe, the main characteristics are the focus size and the number of photons collected in it (efficiency). In Bragg-Fresnel focusing elements, both characteristics are related to the minimum zone size. However, an increase in the efficiency can be achieved by creating compound elliptical zone plates. To analyze the operation of zone plates of different constructions, an effective program for calculating the image of a point source was developed. The main advantage of the program is a new method for the fast calculation of Kirchhoff integral, detailed description of which is presented in Appendix A. The program allows to obtain a diffraction pattern from real lenses as well as to analyze their changes at different deviations of the lens position from the ideal position with respect to an incident X-ray beam. Different constructions of compound elliptical zone-plates designed on the base of the program and then fabricated are described in the work. The results of using a high-aperture Bragg-Fresnel lens for microfluorescent analysis and microdiffraction are presented.

We present a new X-ray microdiffraction method coupled to microfluorescence for phase identification of a sample of 10 mu m in size. This method uses the high brilliance of synchrotron radiation, which allows an X-ray focus of a few square micrometers. Thus, diffraction patterns of 25-mu m inclusions are obtained. We present in this paper an example of application of this method, i.e. the identification of non metallic inclusions in an archaeological iron ingot.

We present one of the first microdiffraction experiments performed with a photon microprobe. It allows the phase identification in 20 μm size, of inclusions collected in ancient ferrous artefacts

The advent of synchrotron radiation and the recent development of X-ray optics have rendered possible the realization of X-ray fluorescence microprobes. Various arrangements allow to obtain micrometer size hard X-ray beams with enough flux to undertake elemental mapping of trace elements. Associated with microdiffraction or with extended X-ray absorption fine structure studies, these microprobes will become a very interesting tool for material characterization.