Improvement of spatial resolution of monochromatic X-ray CT using synchrotron radiation

X-ray computed tomography using synchrotron radiation (SR) as an X-ray source potentially provides CT images of improved quality, since SR produces tunable, monochromatized and collimated X-ray beams of high flux density. We can obtain CT images of small samples rapidly with better spatial resolution and constrast; we can also obtain the spatial distribution of a specific element using the absorption edge. In this paper, a method for improving the spatial resolution of such a system is presented, involving the magnification of projection images using asymmetric diffraction. First, the modulation transfer function (MTF) of projection images of an X-ray test chart is measured in order to evaluate the spatial resolution. Next, using this method, we show CT images of several industrial materials with spatial resolution of 15 ∼ 30 μm and demonstrate the usefulness of SR-CT with a high spatial resolution. (author)