Anders Rindby

Use of microscopic XRF for non‐destructive analysis in art and archaeometry

The various application possibilities of microscopic x-ray fluorescence and associated methods for the characterization and provenance analysis of objects and materials of cultural heritage value are discussed by means of a number of case studies. They include the trace analysis of historic glass, the analysis of corroded coins and statues in bronze and silver and the study of inks on historical documents. These studies are conducted by means of micro-XRF instruments installed at synchrotron beamlines and by means of laboratory equipment, some of which is easily transportable to the museum or archaeological site where the objects of interest are located. Copyright

A 200 μm X-ray microbeam spectrometer

Abstract An X-ray beam with a diameter of 200 μm has been developed with the use of a small glass capillary and a conventional diffraction X-ray tube. The intensity, spectral distribution and the angular dispersion have been investigated. The microbeam together with a Si(Li) detector has been used for trace element analysis in single hair strands and other biological tissues. Detection limits are given.

Interpretation of capillary generated spatial and angular distributions of x rays: Theoretical modeling and experimental verification using the European Synchrotron Radiation Facility Optical beam line

Using a detailed ray-tracing code for capillary optics, interpretation is given for parallel bore hole and tapered capillary generated far-field images. These images can be used to indicate the presence of various types of surface imperfections (i.e., surface roughness or waviness) or shape distortions of the optical device. The capillary output patterns were recorded at the optical beam line of the European Synchrotron Radiation Facility by using a monochromatic, highly parallel incident synchrotron beam. Capillaries of various dimensions were studied, with inlet diameters in the range of 30–70 μm, outlet diameters of 22–42 μm, and capillary length values ranging from 10 to 23 cm. The far-field images were taken at a distance of 10–11 cm from the capillary exit using a high resolution charge coupled device camera. By comparisons of simulated and experimental capillary output patterns, the effects of surface roughness/waviness, as well as axial distortions are studied with respect to the angular distribution of the generated capillary beam.Using a detailed ray-tracing code for capillary optics, interpretation is given for parallel bore hole and tapered capillary generated far-field images. These images can be used to indicate the presence of various types of surface imperfections (i.e., surface roughness or waviness) or shape distortions of the optical device. The capillary output patterns were recorded at the optical beam line of the European Synchrotron Radiation Facility by using a monochromatic, highly parallel incident synchrotron beam. Capillaries of various dimensions were studied, with inlet diameters in the range of 30–70 μm, outlet diameters of 22–42 μm, and capillary length values ranging from 10 to 23 cm. The far-field images were taken at a distance of 10–11 cm from the capillary exit using a high resolution charge coupled device camera. By comparisons of simulated and experimental capillary output patterns, the effects of surface roughness/waviness, as well as axial distortions are studied with respect to the angular distribut...

Spatial distribution of metal ions in spruce wood by synchrotron radiation microbeam X-ray fluorescence analysis

Summary The possibility of using synchrotron radiation microbeam X-ray fluorescence (μ -XRF) for the determination of the morphological distribution of inorganic elements in wood has been investigated. A number of samples were analyzed and some of the results are presented in this paper. The new application of the method showed good results and it was concluded that the technique is useful for specific in situ metal ion analysis of wood. One of its special advantages is that it is a non-destructive method, which may allow analysis of the same sample before and after a chemical treatment. This study shows the natural distribution of a selection of metal ions in wood. Some differences in the distribution and amount of certain metals could also be observed in a sample that had been subjected to treatment with an EDTA-solution.

Microdiffraction studies of bone tissues using synchrotron radiation

This is the first report on a series of studies of the crystallinity of bone tissues. The measurements were done at the microfocused diffraction beamline at ERSF (European Synchrotron Radiation Facility) as a feasibility test on various aspects on microdiffraction analysis. Beside the crystal structure, crystallite size distribution and preferential orientation were also studied, with a spatial resolution of 7 microm. The experiments were performed at the microfocus beam line 1 at European Synchrotron Radiation Facility (ESRF). The samples were longitudinal and transversal cuts from human femoral shafts. Over 65 diffraction lines from apatite structure could be identified. The results show that the bone crystallites seem to be oriented in two orthogonal directions, one parallel with the Haversian system and the other perpendicular following the lamellas curvature. Peak width analysis shows that the crystallites are about 25-40 nm along the c-axis with a width of about 10 nm. The result also shows that the peak width is somewhat larger close to the haversian canal compared with the outer region of the osteon.

Improved capillary optics applied to microbeam x‐ray fluorescence: Resolution and sensitivity

A new and improved type of x‐ray capillary optics unit (ellipsoidal), is developed, tested, and characterized using a table‐top x‐ray microbeam setup. The beam profiles of the x‐ray beams generated by the 7.5 μm ellipsoidal capillary were constructed from ‘‘knife‐edge’’ scans across the beam. The detection limits for various elements were determined, and the spatial resolution, when the beam was used in scanning mode, was demonstrated.

A table‐top x‐ray microbeam scanning facility

The x‐ray microbeam scanning facility in our laboratory at Chalmers University of Technology/Goteborg University is described in terms of optical and mechanical design, imaging capacity, spatial resolution, and sensitivity. Different types of visualization of the elemental distribution are demonstrated and application of image processing is discussed. Examples of applications in the field of single‐particle analysis as well as tree ring analysis are given. Future perspectives of the technique are also discussed.

Development of a low power monoenergetic X-ray tube for trace element analysis

Abstract A system for trace elemental analysis by X-ray spectrometry has been developed. The system consists of a secondary fluorescence low power X-ray tube, a Si(Li) detector with associated pulse processing system and minicomputer. The spectrometer has been used for routine analysis of blood specimens.

Micro-distribution of heavy elements in highly inhomogeneous particles generated from μ-beam XRF/XRD analysis

Abstract By simultaneously recording X-ray fluorescence intensities and X-ray diffraction pattern at a microscopic level highly heterogeneous samples of fly-ash particles have been analyzed. From the data achieved by this combined experiment, the main minerals in the particles have been identified and the size distributions of these minerals have also been determined. The distribution of heavy elements, recorded from their fluorescent intensity, is presented and the impact of sample surface topology and anomalous attenuation is discussed. Estimates of the concentration of the these heavy elements are given and correlation analysis has been performed indicating that most of these elements seem to appear at the surface of the fly-ash particles.

Trace Element Analysis in Thick Organic Specimens by Photon Excited X-ray Fluorescence

Photon excited X-ray fluorescence has been used for quantitative trace element analysis in thick organic specimens. The evaluation of matrix effects has been facilitated by use of a PDP-11 computer which can be connected on line to the data collecting system. The handling of blood serum samples is discussed.