Kinematic diffraction is an approximation for diffraction of waves. It assumes that the waves are only scattered once, neglecting multiple scattering. For linear wave equations, it involves summing the contribution of the partial waves emanating from different scatterers, where only the incident field drives the scattering.
In the kinematic approximation, the scattered amplitude can be written as the Fourier transform of the scattering density,
where is the scattering vector and is the scattering density. The corresponding diffracted intensity is proportional to the squared magnitude of the amplitude,
↑Humphreys, C J (1979-11-01). "The scattering of fast electrons by crystals". Reports on Progress in Physics. 42 (11): 1825–1887. doi:10.1088/0034-4885/42/11/002. ISSN0034-4885.