High Quality Content by WIKIPEDIA articles! Diffraction topography (short: "topography") is an X-ray imaging technique based on Bragg diffraction. Diffraction topographic images ("topographs") record the intensity profile of a beam of X-rays (or, sometimes, neutrons) diffracted by a crystal. A topograph thus represents a two-dimensional spatial intensity mapping of reflected X-rays, i.e. the spatial fine structure of a Bragg spot. This intensity mapping reflects the distribution of scattering power inside the crystal; topographs therefore reveal the irregularities in a non-ideal crystal lattice. X-ray diffraction topography is one variant of X-ray imaging, making use of diffraction contrast rather than absorption contrast which is usually used in radiography and computed tomography (CT).