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Many physical and mechanical properties of crystalline materials depend strongly on their internal structure, which is typically organized into grains and domains on several length scales. Here we present dark-field X-ray microscopy; a non-destructive microscopy technique for the three-dimensional mapping of orientations and stresses on lengths scales from 100 nm to 1 mm within embedded sampling volumes. The technique, which allows ‘zooming’ in and out in both direct and angular space, is demonstrated by an annealing study of plastically deformed aluminium. Facilitating the direct study of the interactions between crystalline elements is a key step towards the formulation and validation of multiscale models that account for the entire heterogeneity of a material. Furthermore, dark-field X-ray microscopy is well suited to applied topics, where the structural evolution of internal nanoscale elements (for example, positioned at interfaces) is crucial to the performance and lifetime of macro-scale devices and components thereof., The internal structure of materials determines many of their physical and mechanical properties. Here, the authors have developed a non-destructive X-ray microscopy technique for layer-by-layer mapping of crystallographic orientations and stresses to obtain a three-dimensional reconstruction of a material.

Due to its outstanding thermal properties, diamond is an attractive alternative to silicon as a monochromator material for high intensity X‐ray beams. To date, however, the practical applications have been limited by the small size and relatively poor crystallographic quality of the crystals available. The ESRF Diamond Project Group has studied the perfection of diamonds in collaboration with industry and universities. The group has also designed and tested different stress‐free mounting techniques to integrate small diamonds into larger X‐ray optical elements. We now propose to develop a water‐cooled Bragg‐Bragg double crystal monochromator using diamond (111) crystals. It will be installed on the ESRF undulator beamline, ID06, for testing under high heat load. This monochromator will be best suited for the low energy range, typically from ∼3.4 keV to 15 keV, due to the small size of the diamonds available and the size of the beam footprint. This paper presents stress‐free mounting techniques studied using X‐ray diffraction imaging, and their thermal‐mechanical analysis by finite element modelling, as well as the status of the ID06 monochromator project.