Nanoscale Dark-Field Imaging in Full-Field Transmission X-Ray Microscopy

Abstract

The dark-field signal uncovers details beyond conventional X-ray attenuation contrast, which is especially valuable for material sciences. In particular, dark-field techniques are able to reveal structures beyond the spatial resolution of a setup. However, its implementation is yet limited to the micrometer regime. Therefore, we propose a technique to extend full-field transmission X-ray microscopy by the dark-field signal. The proposed method is based on a well-defined illumination of a beam-shaping condenser, which allows to block the bright-field by motorized apertures in the back focal plane of the objective's lens. This method offers a simple implementation and enables rapid modality changes while maintaining short scan times, making dark-field imaging widely available at the nanometer scale.

Updated version; revised according to the comments from the peer review. There were only minor changes. In general we mainly added more detailed explanations. We changed the title, extended sections 2.1., 2.2., 2.3. and 3., extended Fig. 1 to better illustrate the differences between the two imaging modes, and made some slight adjustments in section 4. for clarifications