The central element of the platform is a microtomograph that enables three-dimensional imaging of samples using X-ray absorption constrast. Its special design, which was unique when it was commissioned in 2011, enables the microstructures of a wide range of materials and their evolution under stress to be observed on a wide range of scales. Its two X-ray generators complement each other. The first, known as the "nanofocus", enables the finest resolutions to be achieved, down to the micrometer. The second, the "microfocus", produces more intense flows of higher-energy photons (up to 230keV) to penetrate massive samples, typically 15cm of concrete or 15mm of steel. The main imager currently in use digitizes radiographs with 3Kx3K pixel definition and an excellent signal-to-noise ratio. Advanced acquisition modes that combine multiple scans provide 3D images of an entire sample with a definition that can exceed 2800x2800x6000 voxels. Another photon-counting, photon-energy-sensitive imager paves the way for 3D "color" imaging, currently under development.
Thanks to the original design of the frame and rotation plate, the tomograph can support complex devices (up to 100kg) to stress the samples being observed. The range of resources is regularly expanded to meet the needs of research projects: uniaxial mechanical loading (from a few Newtons to 20kN) and triaxial loading (confinement of 20MPa), bending, rheometer, humidity control, gas injection, heating and cooling, etc. Handling the very rich data acquired relies on appropriate computing and storage resources, both for the reconstruction of 3D images, carried out on GPUs, and for their quantitative analysis by image processing, and in particular by correlation of volumetric images giving access to local deformation and damage fields.