INTERFEROMETER FOR QUANTATIVE PHASE CONTRAST IMAGING AND TOMOGRAPHY WITH AN INCOHERENT POLYCHROMATIC X-RAY SOURCE

摘要

An x-ray interferometer arrangement is disclosed comprising only one phase grating (G1) and one amplitude grating (G2). This interferometer can be used to obtain phase contrast images with a standard x-ray tube. Additionall, the new type of interferometer may use a source consisting of an array of individual sub-sources. Each of the sub-sources is individually coherent but mutually incoherent to the other sub-sources. The array of sub-sources may be generated by placing an array of slits, i.e. an additional amplitude grating (G0) close to the source. Such an arrangement makes it possible to use this type of interferometer with a source that provides no spatial or temporal coherence. The setup can therefore be used with larger sources placed at shorter distance of the detector resulting in higher flux densities and thus shorter exposure times. This is of special importance for tomography which requires to acquire images of an object under many (hundreds) viewing angles.