Synchrotron energy-dispersive X-ray diffraction tomography

Energy-dispersive diffraction tomography using white-beam synchrotron X-rays with energies up to 140 keV yields images of the interior features of solid objects up to 50 mm thick. The volume sampled is determined by the geometry of the diffracting lozenge defined by the incident beam, the detector system collimation and the Bragg angle. Using conventional beam slits to form a highly collimated 50 mu m x 50 mu m incident beam and a 40 mu m collimator aperture, we demonstrate on a PEEK phantom that a lateral resolution (transverse to the beam direction) of a few microns can be achieved. The resolution in the direction of the incident beam is necessarily poorer than this since the diffracting lozenge is elongated in this direction, with length increasing rapidly at small angles, There is no evidence of significant contamination of the diffracted intensity by the effects of multiple scattering from outside the primary lozenge. (C) 1998 Published by Elsevier Science B.V.