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.
Specifications:
- X-ray Tube: the x-ray source is a spot stabilized, sealed transmission x-ray tube with a voltage range of 30-160 kV and a maximum output of 10 W; set of 13 filters to tune the beam based on sample size and density.
- Detector: the detector is a high speed large array CMOS flat panel detector with 3,072 x 1,944 pixels, providing a single field of view size of 144 mm (diameter) by 93 mm (height), with a maximum height of 165 mm.
- System stability: granite base vibrational isolation; thermal environment stabilization; low noise detector
- Sample stage: up to 25 kg sample mass capacity
- ACT resolution: Spatial resolution: 0.95 μm; achievable reconstruction voxel size at working distance: 0.5 μm at 0.5 mm; 0.8 μm at 2.5 mm; 2.5 μm at 12.5 mm; 4.0 μm at 25 mm; 12.1 μm at 100 mm
- DCT resolution: grain angular resolution 0.1°; grain detectability 20 μm;
- Acquisition Software: Zeiss Scout-and-scan control system
- Reconstructions ACT: Zeiss XMReconstructor
- Reconstructions DCT: XNovo Technology GrainMapper3D (allcrystal symmetries available)
- Visualizations: ORS Dragonfly Pro for 3D visualization and analysis