A BEAM HARDENING CORRECTION FOR X-RAY MICROTOMOGRAPHY

We propose a correction of the transmitted intensities in X-ray micros copy allowing improved quantification for polychromatic sources, parti cularly in tomographic reconstruction. The correction is based on the application of Beer's law for each energy present in the source spectr um. Knowledge of the source spectrum and the average specimen composit ion are used. The correction is demonstrated on a chemically homogeneo us specimen (a glass capillary filled with glass beads) and on a polyp hasic oil reservoir rock sample. In the former, detection of 20 mu m d efects is demonstrated. In the latter, different minerals, quartz, fel dspath and kaolinite, can be discriminated and their distributions map ped. (C) 1997 Elsevier Science Ltd.