Laboratory-based x-ray dark-field microscopy

We demonstrate the capability of laboratory-based x-ray microscopes, using intensity-modulation masks, to access the submicron length scale in the dark-field contrast channel while maintaining micron resolution in the resolved (refraction and attenuation) channels. The dark-field contrast channel reveals the presence of ensembles of samples' features below the system resolution. Resolved refraction and attenu-ation channels provide multimodal high-resolution imaging down to the micron scale. We investigate the regimes of modulated and unmodulated dark field as well as refraction, quantifying their dependence on the relationship between feature size in the imaged object and aperture size in the intensity-modulation mask. We propose an analytical model to link the measured signal with the sample's microscopic proper-ties. Finally, we demonstrate the relevance of the microscopic dark-field contrast channel in applications from both the life and physical sciences, providing proof-of-concept results for imaging collagen bundles in cartilage and dendritic growth in lithium batteries.