High resolution 3D reconstructions of rocks and composites

Ten mu m resolution 30 representations of different media, were obtained with a laboratory computer microtomograph developed from an electron microprobe column. From the original electron microprobe, only minor modifications have been required, indeed several of the utilities of the microprobe have been used to ensure high resolution radiography (2 mu m). The impact of the electron beam focused onto a thin film is used to form a "point" X-ray source and the radiographic image of the sample is acquired on a CCD camera, A specimen rotation mechanism allows multiple radiograph acquisition and reconstruction of the X-ray attenuation 30 cartography. Since X-ray attenuation is directly: related to density and atomic number, the microscanner provides 30 cartographs of the different phases present in the sample. System performances have been evaluated on various samples, mainly rocks and composites. Comparison with scanning electron micrographs was used when possible to validate the reconstructions. Results are mostly qualitative bur already: show the potential of the technique in describing 30 connectivity and topology of pore networks or 30 orientation of fibres in composites.