Full-field XRF computed tomography (FF-XFCT)
3D elemental imaging from full-field fluorescence projections.
Full-field X-ray fluorescence computed tomography (FF-XFCT) extends full-field XRF imaging into three dimensions. The sample is illuminated over an area, the X-ray fluorescence is imaged onto the detector, and a series of projections is acquired while the sample rotates.
A pnCCD based Colour X-Ray Camera (CXC) enables FF-XFCT because it records both the position and energy of each detected photon. This allows spectroscopic separation of fluorescence lines while preserving spatial information for tomographic reconstruction.
From 2D maps to 3D elemental volumes
FF-XFCT uses the same principle as XRF mapping, but adds rotation to recover depth. Each projection contains spatially resolved spectra. Reconstruction combines many projections to estimate the 3D distribution of selected elements.
Key points
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Elemental information in three dimensions, not only surface contrast
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Multi-element data from one measurement set
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Direct link between structure and chemistry in the same sample volume
Why full-field matters
Scanning XRF tomography can require tight beam focusing, raster scans, and long acquisition times. Full-field approaches replace spatial scanning with an imaging geometry using a sheet beam. The measurement becomes a rotation series rather than a full 3D raster scan.
Key points
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No point-by-point spatial scanning for each projection
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Fewer motion axes and simpler scan coordination
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Naturally aligned spectral and spatial data in each projection
Imaging optics are required
X-ray fluorescence is emitted approximately isotropically. FF-XFCT therefore requires optics or an aperture between the sample and detector to encode spatial origin onto the sensor.
Common approaches include:
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Polycapillary imaging optics for direct spatial mapping
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Pinhole projection for simple, flexible geometries
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Coded apertures for advanced full-field configurations
Key points
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Optics define field of view and spatial mapping
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Energy-resolved detection keeps full spectroscopy after imaging
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Geometry and optic choice set the practical trade space
Depth effects and reconstruction
Fluorescence originates inside the sample. The excitation beam attenuates on the way in, and fluorescence can self-absorb on the way out. Reconstruction therefore relies on modelling and correction to recover depth distributions reliably.
In practice, many workflows combine FF-XFCT with transmission information or attenuation models to improve quantitative accuracy.
Key points
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Accounts for excitation attenuation and fluorescence self-absorption
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Uses modelling and correction during reconstruction
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Benefits from complementary transmission data when available
Learn more
If you are interested in FF-XFCT, or would like to discuss optics, geometry, and realistic boundary conditions for your sample and beamline, please contact us to discuss your application.
If you are specifically looking for commercially available systems built on this core technology, explore our range of Colour X-Ray Camera (CXC) products here.