Real-time image-content-based beamline control for smart 4D X-ray imaging
Synchrotron-radiation-based
imaging diagnostics has become a reliable tool for systematic examination of
chemical and biological samples in various research areas. Progress in photon
flux density and advanced pixel array detectors with high spatial resolution,
low noise and fast read-out, as well as fast and high-precision positioning
manipulators, permit much reduced measuring time compared with solutions based
on laboratory sources. Using these technologies, synchrotron radiation computed
tomography (SRCT) experiments can be extended to achieve data acquisition times
of less than a second for a complete three-dimensional (3D) dataset. Combined
with optical flow analysis, this has enabled the development of cine-tomography, a technique that allows
for the characterisation of four-dimensional (4D) spatiotemporal structure
evolution of technical and biological processes.
Synchrotron radiation computed laminography (SRCL) has extended the applicability of 3D synchrotron imaging to thin plate-like objects that otherwise prohibit homogeneous transmittance using conventional tomographic scans. It is especially suited to flat specimens which cannot be trimmed down and thus do not fit into the detector’s field of view.
Due to the complexity of the experimental setup, SRCT and in particular SRCL pose challenging problems for automation and software-controlled experiment. For a successful automated scan, the imaging and sample apparatus must be aligned and positioned properly, the sample be stabilised and the measurement setup controlled during the imaging process.
A team of scientists from Germany, France and Russia [Vogelgesang et al. (2016). J. Synchrotron Rad. 23, 1254-1263; doi:10.1107/S1600577516010195] address the outlined experimental challenges by developing concepts, tools and methods for smart image recording.
Successfully employed both SRCT and SRCL are used with a large variety of contrast modes such as phase contrast, fluorescence and diffraction contrast allowing many applications in materials research, microsystem technology, cultural heritage, palaeontology and biology.
