PHASE-CONTRAST IMAGING WITH HARD X-RAYS. S.W. Wilkins, T.J.Davis, D. Gao, T.Gureyev, A. Pogany, and A.W. Stevenson, CSIRO, Division of Materials Science and Technology PB 33 Clayton South MDC Vic 3169 Australia

Entirely new methods of X-ray imaging have recently been developed involving phase-contrast rather than conventional absorption contrast. These methods are sensitive to the real part of the X-ray refractive index () and more particularly to the quantity itself or to derivatives of this quantity. In the case of conventional X-ray interferometry [1,2], it is the phase (modulo 2) which is detected while for other methods involving crystal analyzer systems [3-6], the quantity detected is a phase gradient. In the present paper, emphasis will be given to outlining different approaches to differential phase-contrast imaging and to understanding the physical nature of image formation in different regimes.

Examples of phase-contrast images for different cases will also be presented to help illustrate the key features of some of these approaches.

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