Tracking based, high-resolution single-shot multimodal x-ray imaging in the laboratory enabled by the sub-pixel resolution capabilities of the MÖNCH detector

Abstract

The simultaneous retrieval of x-ray attenuation, phase, and scattering using multimodal imaging techniques is finding increasing use in a range of applications, from medicine to materials science. Most techniques rely on the mechanical movement of an optical element (e.g., a grating or a mask) to obtain the multimodal images. While single-shot approaches exist, they typically employ detector pixels smaller than the grating period, often with low detection efficiency, and are limited in resolution unless either the sample or the optical element is displaced in various positions and multiple frames are collected. In this paper, we replace mechanical motion with the MÖNCH detector's capability to reach sub-pixel resolutions by interpolating between neighboring pixels collecting the charge generated by a single x-ray event. This enabled us to obtain the pilot demonstration of a laboratory-based high-resolution, single-shot multimodal imaging technique capable of simultaneously retrieving attenuation, directional differential phase, and scatter images, without any mechanical movement. We show that our proof-of-concept setup enables a single-shot resolution of 19.5 μ m and that the resulting images provide sufficient information to produce a reliable sample thickness map. Furthermore, we demonstrate that the setup is capable of producing single-shot directional scattering images, while leaving open the option to further increase the resolution by using sample dithering.