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X-ray diffraction is a generic term for phenomena associated with changes in the direction of X-ray beams due to interactions with the electrons around atoms. It occurs due to elastic scattering , when there is no change in the energy of the waves.
An X-ray diffraction pattern of a crystallized enzyme. The pattern of spots (reflections) and the relative strength of each spot (intensities) can be used to determine the structure of the enzyme. The relative intensities of the reflections provides information to determine the arrangement of molecules within the crystal in atomic detail.
X-ray optics is the branch of optics dealing with X-rays, rather than visible light. It deals with focusing and other ways of manipulating the X-ray beams for research techniques such as X-ray diffraction , X-ray crystallography , X-ray fluorescence , small-angle X-ray scattering , X-ray microscopy , X-ray phase-contrast imaging , and X-ray ...
Usually X-ray diffraction in spectrometers is achieved on crystals, but in Grating spectrometers, the X-rays emerging from a sample must pass a source-defining slit, then optical elements (mirrors and/or gratings) disperse them by diffraction according to their wavelength and, finally, a detector is placed at their focal points.
Bragg diffraction (also referred to as the Bragg formulation of X-ray diffraction) was first proposed by Lawrence Bragg and his father, William Henry Bragg, in 1913 [1] after their discovery that crystalline solids produced surprising patterns of reflected X-rays (in contrast to those produced with, for instance, a liquid).
Inelastically scattered X-rays have intermediate phases and so in principle are not useful for X-ray crystallography. In practice X-rays with small energy transfers are included with the diffraction spots due to elastic scattering, and X-rays with large energy transfers contribute to the background noise in the diffraction pattern.
The Ewald sphere is a geometric construction used in electron, neutron, and x-ray diffraction which shows the relationship between: the wavevector of the incident and diffracted beams, the diffraction angle for a given reflection, the reciprocal lattice of the crystal. It was conceived by Paul Peter Ewald, a German physicist and ...
In crystallography, the R-factor (sometimes called residual factor or reliability factor or the R-value or R Work) is a measure of the disagreement between the crystallographic model and the experimental X-ray diffraction data - lower the R value lower is the disagreement or better is the agreement.