X-ray fluorescence microtomography: experiment and reconstruction

First experimental results of fluorescence microtomography with 6 micrometer resolution obtained at the ESRF are described. The set-up comprises high quality optics (monochromator, mirrors, focusing lenses) coupled to the high energy/brilliance/coherence of the ID 22 undulator beamline. The tomographic set-up allows precise measurements in the 'pencil-beam' geometry. The image reconstruction is based either on the filtered back-projection (FBT) method or on a modification of the algebraic reconstruction method (ART) but includes simplifications of the model. The quality and precision of the 2D reconstructed elemental images of two phantom sample are encouraging. The method will be further refined and applied for the analysis of more complex inhomogeneous samples.