Zeiss Xradia Crystal CT

This instrument can be used in two different modes: Absorption Contrast Tomography (ACT): the sample is rotated in small steps around the vertical axis and absorption images are recorded for each orientation; those images are then recombined into a 3D reconstruction of the mass-density of the object. Diffraction Contrast Tomography (DCT): the diffracted beams generated by the crystalline structure of the polycrystalline sample are intercepted by a planar detector and used, along with the ACT signal, to reconstruct the 3D microstructure of the sample, including the crystallographic orientations of the individual grains. In the DCT mode, the standard data acquisition mode is augmented by three advanced acquisition modes: helical phyllotaxis for cylindrical samples with high aspect ratios; helical phyllotaxis raster, for samples that are wider than the field of view, and helical phyllotaxis HART, for flat or plate-like samples. All modes allow for grain microstructures down to about 20 μm grain size to be studied in a non-destructive way, opening the path to in-situ observations.