ON THE POSSIBILITIES OF X-RAY PHASE-CONTRAST MICROIMAGING BY COHERENTHIGH-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 co ntrast imaging is proposed and used to record holographic images from organic samples of 10-100 mu m at energy 10-50 keV with the contrast u p 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 r equirements, and energy range applicability. It is found that for carb on-based fibers a detectable size with 2% contrast is 0.1 mu m for 10 keV and -1 mu m for 100 keV. It is demonstrated that the fine interfer ence structure of the image is very sensitive to the shape, density va riation, and internal structure of the sample. Some prospects for the practical use and future development of the new coherent techniques su ch as phase contrast microscopy, microtomography, holography, and inte rferometry at high energies are also discussed. (C) 1995 American Inst itute of Physics.