A peak in the scattering pattern in X-ray diffraction of a crystal. The intensity of Bragg peaks is proportional to the square of the number of the scatterers. If X-ray scattering from a solid produces Bragg peaks this indicates that the solid has long-range order. Bragg peaks are named after Sir William Henry Bragg, who discovered them in 1904. The scattering of X-rays from a set of planes in a crystal that gives rise to Bragg peaks is called Bragg scattering.