Walk-in X-ray radiation protection cabin

Walk-in X-ray radiation protection cabin with integrated experimental platform

Techniques: X-ray computed tomography / Talbot-Lau grating interferometer

Walk-in X-ray radiation protection cabin
View of the cabin
© FIBRE, Bremen

Integrated experimental platform
Cabin with in-situ experiments
© FIBRE
Optical bench
Experimental platform
© FIBRE, Bremen
Talbot-Lau grating interferometer
Talbot-Lau grating interferometer on the experimental platform
© FIBRE

Investigation area: 3D and 4D Materials Analytics
Techniques X-ray computed tomography / Talbot-Lau grating interferometer
Manufacturer PROCON
Fabrication year 2024
Supported by Federal Ministry for Economic Affairs and Climate Action; INNO-KOM IZ240042; IZ190032
Measured quantity: 3D-shape; defects; interfaces; volume
Main application:
- Non-destructive testing (NDT) of metals, compound materials, opto-electronic components, etc.
- Testing and research platform for X-ray applications
- 4D Experiments

Technical aspects
- flat-panel detector; detector size 140 x 120 mm
- read-out rate at least 40 fps
- measuring field extension to 280 x 240 mm (max. component size 250 x 220 mm)
Microfocus x-ray tube - 150 kV / 75 W, > 3 ?m resolution
Additional measurement possibilities

Talbot-Lau grating interferometer

In-situ experiments

In-situ experiments conducted inside the walk-in radiation protection cabin benefit from a combination of high-resolution X-ray imaging and an open, Python-based control environment. The large optical bench provides ample space for integrating mechanical testing systems, climate chambers and complex sample holders. Researchers can perform tensile, compression, and bending tests. Individually designed experiments can also be integrated and implemented. The Python-based software architecture enables direct integration with the RosCT software, offering precise control over the scanning process, automated test sequences and advanced image reconstruction. This flexible setup supports customised workflows and data analysis pipelines that can be adapted to specific research requirements, facilitating the study of damage progression, pore evolution and structural changes under realistic loading conditions. The flexibility of the hardware configuration, combined with an open software ecosystem, makes this system ideal for advanced material characterisation and process development. An in-situ stage for tensile, compression and bending tests, equipped with acoustic emission technology for crack detection, is already available.

Advanced imaging techniques

This advanced, grating-based X-ray technology enables multiple contrast modes to be acquired in a single scan. It combines absorption contrast (AC), differential phase contrast (DPC) and dark-field contrast (DFC) to generate detailed, complementary information about the internal structure of a sample. Absorption contrast visualizes the attenuation of X-rays by dense materials, while differential phase contrast improves the visibility of interfaces and subtle density differences. Dark field contrast is highly sensitive to small-angle scattering caused by microstructural features such as cracks, voids and fiber networks. Together, these contrasts allow researchers to detect fine defects and anomalies that remain invisible in conventional CT imaging. The technique also significantly increases contrast when examining materials with very low (e.g. carbon fiber vs. matrix) or very high (e.g. metal insert vs. FRP) density variance. So that the limitations of conventional X-ray CT can be overcome.

Photo of a cotton fruit. The following photos show X-ray images in different contrast modes. Conventional image (AC). (DFC): the cotton fibres become visible. (DPC): contrast enhancement in the cotton seeds.

Principle of Talbot-Lau grating interferometer

The interferometer's design integrates three precision gratings, where the first grating (G0) creates spatial coherence of the X-ray beam, the second grating (G1) functions as a phase grating producing periodic phase shifts, and the third grating (G2) acts as an analyser grating that samples the resulting interference pattern arranged along the optical axis to generate interference patterns that are computationally reconstructed into high-fidelity volumetric images. Phase stepping is achieved by translating the analyser grating (G2) perpendicular to the X-ray beam, which allows measurement of phase shifts across multiple positions. This approach leverages the Talbot effect, where periodic gratings form self-images at defined distances behind the grating.