The high x-ray flux of synchrotron sources offers the possibility of time-resolved micro-CT experiments to explore the 3D structure of systems which are changing with time. At the Imaging and Medical Beamline at the Australian Synchrotron, hardware upgrades have made it possible to acquire a micro-CT scan in as little as 10s. This capability is illustrated with two examples showing evolution of 3D structures in time.
The first example is a study of gas diffusion into coal. Coal is an important source rock for methane and also a potential reservoir for carbon storage. Key to these applications is an understanding of how gases move through the micro-structure of this very complex and heterogenous material. This study was performed by observing the flow of xenon gas into a selection of coal samples. K-edge subtraction was used to separate the 3D images of the coal from the xenon in order to get a quantiative understanding of the spatial and temporal variation in gas take-up .
The second example is a study of the rising and baking of a range of bread doughs made with different formulations. These experiments required the fastest scanning speeds the IMBL was capable of at the time, taking about 20s per scan. The dough structure was observed during rising and then baking to investigate the differences between the behaviour of dough made from low and high protein flour, and with different salt additives..
Rapid time-resolved scanning presents an additional challenge compared to more typical micro-CT experiments as the quantity of data generated in a single 3 day experiment can easily be several terabytes. The dough experiment for example generated over 460 individual CT scans requiring processing and analysis. Approaches to dealing with these challenges will be addressed.