X-Ray Monochromators
A monochromating crystal behaves in X-ray spectrometry similar to diffraction grating in optics. When rotated with respect to the incident polychromatic beam, the crystal will diffract at Theta angle from crystal lattice the spectral component at wavelength lambda along the direction that satisfies Bragg's law, namely: 2d sin(Theta) = n lambda, where integer n refers to the diffraction order.
