On the possibilities of x-ray phase contrast microimaging by coherent high-energy synchrotron radiation

Coherent properties of the x-ray beam delivered at the ESRF allow the observation of very weak perturbations of the wave front, resulting in the phase contrast. A straightforward experimental setup for phase contrast imaging is proposed and used to record holographic images from organic samples of 10–100 μm at energy 10–50 keV with the contrast up to 50%–100%. The theory of phase contrast imaging is considered and some theoretical estimations are made to reveal the performance of the proposed technique in terms of resolution, sensitivity, geometrical requirements, and energy range applicability. It is found that for carbon-based fibers a detectable size with 2% contrast is 0.1 μm for 10 keV and −1 μm for 100 keV. It is demonstrated that the fine interference structure of the image is very sensitive to the shape, density variation, and internal structure of the sample. Some prospects for the practical use and future development of the new coherent techniques such as phase contrast microscopy, microtomography, holography, and interferometry at high energies are also discussed.