A dynamical theory calculation, based on Bloch wave expansion, is developed to explain spin-scho resolved grazing incidence scattering measurements on a diffraction grating. The theory provides a detailed description of the scattering process and the behavior of the neutron wavefunction in the vicinity of the grating.

Two alternative theories that describe neutron scattering from periodic nanostructures are compared with each other and with experimental data. Dynamical scattering theory agrees with experiment for all scattering geometries, while the simpler phase-object approximation can only be used reliably under certain conditions.