Phase‐contrast computed microtomography with 50 keV synchrotron x‐rays

The possibilities to determine the internal structure of low density materials by a simple microtomography setup with high energy synchrotron x‐rays are demonstrated experimentally. The coherent properties of a 50 keV x‐ray beam at the ESRF wiggler beamline are used to observe phase‐contrast images of a boron fiber, which has negligible absorption in this energy range. Images of the boron fiber are recorded with a high‐resolution x‐ray film at various distances up to 2 m. For microtomography studies, 61 images are taken over an angular range of 180 degrees. In the reconstructed cross sections, the hollow, 15‐mm‐diameter core of the fiber is clearly visible.