The Use of a Scanning X‐ray Microprobe for Simultaneous XRF/XRD Studies of Fly‐Ash Particles

With the opening of the first real `third‐generation' synchrotron source in Grenoble, in fall 1994, X‐ray sources of unprecedented brilliances and qualities became available to the scientific community. Different X‐ray analytical techniques could now be applied on a level that was unimaginable only a decade ago. Here are some preliminary results from an experiment where different analytical techniques have been applied on a micrometer level carried out at the most powerful synchrotron microbeam currently available in the world, the microfocus beamline (BL1) at ESRF. This beamline can now provide micrometer‐sized X‐ray beams with a flux density up to 10 10 photons μm −2 at an energy of 13 keV and with a bandwidth of 10 –4 . In this experiment, X‐ray diffraction and X‐ray fluorescence have been combined in order to obtain a precise and comprehensive micro‐analytical description of micrometer‐sized fly ash particles. These types of particles are heavily inhomogeneous with a very irregular shape that makes them inaccessible to conventional micro‐analysis. The experiment was performed in a scanning mode and two‐dimensional images of different analytical information were reconstructed from the data recorded during the scan. The major features and limitations of this micro‐analytical technique will be outlined and different examples on how the analytical information can be used for generating two‐dimensional images of the sample will be demonstrated and discussed.