Energy Resolved X-Ray Diffraction CT

Low angle x-ray scattering at diagnostic energies in narrow beam geometry is due to coherent (Rayleigh) and incoherent (Compton) scattering. It has been found that single coherent scatter dominates below 10 deg. Interference effects with coherent scatter leads to diffraction patterns which differ from material to material. A technique, analogous to conventional CT, allows the reconstruction of the 2D distribution of the x-ray diffraction properties within an object slice, as demonstrated recently? Use of the bremsstrahlung spectrum of an x-ray tube permits short measuring times, but causes a significant energy broadening of the diffraction curves, thus deteriorating the maximum contrast obtainable by diffraction imaging. With energy resolved photon counting of the scattered x-ray quanta this broadening can be corrected, yielding an image contrast approaching that of a monochromatic x-ray source.