Mott scattering, also referred to as spin-coupling inelastic Coulomb scattering, is the separation of the two spin states of an electron beam by scattering the beam off the Coulomb field of heavy atoms. It is named after Nevill Francis Mott, who first developed the theory. It is mostly used to measure the spin polarization of an electron beam. is proportional to the degree of spin polarization P according to A = SP, where S is the Sherman function. The Born approximation of the diffraction of a beam of electrons by atomic nuclei is an extension of Mott scattering.