Surface scattering of X-rays

To investigate dynamics in thin films with NRS one has to enhance the surface sensitivity of the method using the grazing incidence geometry. A confrontation with surface X-Ray scattering techniques is inevitable. This section is a very short introduction into X-ray scattering in thin films and multilayers. Only electronic scattering is treated. The resonant nature of the NRS method, necessary to investigate dynamics, will be introduced in chapter_Moess. The notation is based on the book ``Elements of modern X-Ray Physics'' [17].