A multi-purpose imaging endstation for high-resolution micrometer-scaled sub-second tomography.

Time-resolved imaging of dynamic processes, ranging from biological in vivo studies to materials under in situ and in operando conditions, requires a flexible endstation capable of controlling complex components that interact in different configurations and at high speeds. At the X02DA TOMCAT beamline we have recently achieved in situ tomographic measurements at a rate of 20Hz. Independently, we have shown the feasibility of in vivo lung imaging down to the micrometer scale. In the present paper, we discuss the latest developments in view of instrumentation and the accompanying components for achieving these two types of measurements. As the prime example, we focus on the technical requirements for in vivo tomographic microscopy of the lung at the micrometer scale in terms of acquisition schemes, triggering and radiation dose. We identify ultra-short single-projection exposures combined with accurate triggering capabilities as the main prerequisites to obtain high-quality reconstructions while limiting the X-ray dose imparted on the living sample. The presented endstation offers generic high-speed imaging capabilities, as it is compatible with a variety of experimental setups and suitable for a wide range of time-resolved studies.