High resolution X-ray detector for synchrotron-based microtomography

Synchrotron-based microtomographic devices are powerful, non-destructive, high-resolution research tools. Highly brilliant and coherent X-rays extend the traditional absorption imaging techniques and enable edge-enhanced and phase-sensitive measurements. At the Materials Science Beamline MS of the Swiss Light Source (SLS), the X-ray microtomographic device is now operative. A high performance detector based on a scintillating screen optically coupled to a CCD camera has been developed and tested. Different configurations are available, covering a field of view ranging from 715×715 μm2 to 7.15×7.15 mm2 with magnifications from 4× to 40×. With the highest magnification 480 lp/mm had been achieved at 10% modulation transfer function which corresponds to a spatial resolution of 1.04 μm. A low-noise fast-readout CCD camera transfers 2048×2048 pixels within 100–250 ms at a dynamic range of 12–14 bit to the file server. A user-friendly graphical interface gives access to the main parameters needed for running a complete tomographic scan. This novel device will be used to study the physical structure and chemical composition of biological and technical materials, e.g. enabling pseudo-dynamic testing of bone samples to establish structure–function relationships in simulated osteoporosis or enabling non-destructive testing during the development of modern composite materials.