Theoretical study of multilayer x-ray mirrors with a wide spectral band of reflection

Recent progress in the manufacturing of X-ray multilayers has opened up new possibilities in the field of hard xray optics allowing to produce wide bandpass optical elements through the design of depth-graded multilayer coatings. However, the inverse problem consisting of inferring the composition profile of the multilayer has only been addressed in a semi-empirical way, which encouraged us to develop a new (theoretical) approach.