Diffraction vector: difference between the wave vector of the scattered wave and the incident wave
Structure factor: interferences of waves scattered by the atoms inside the cell
Shape factor: interferences of waves scattered by the different cells
When the diffraction vector K stays on the same direction, this means that wave vectors of the incidence and scattered waves move symetrically
On a single crystal, there is diffraction when the diffraction vector K meet the reciprocal lattice
On a powder, there is diffraction when the diffraction vector K meet the sphere formed by the node of all the reciprocal lattice
When the incidence wave vector is fixed, the possible diffraction vectors form a sphere called the Ewald sphere or reflection sphere
The intersection of the sphere of the nodes of the reciprocal lattice and the Ewald sphere show that the wave vector of the diffused wave whene there is diffraction form a cone
Limiting sphere: obtained by the rotation around the origin of the refelction(Ewald) sphere
Rotation of the Ewald sphere and Bragg-Brentano geometry (direction of the diffraction vector fixed)
Drawing explaining the principle behind two-slit diffraction.
Bragg diffraction from a cubic lattice
Illustration of two-slit diffraction, based on a sketch by Thomas Young
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