Huang, Q.; Kozhevnikov, I.; Sokolov, A.; Zhuang, Y.; Li, T.; Feng, J.; Siewert, F.; Viefhaus, J.; Zhang, Z.; Wang, Z.: Theoretical analysis and optimization of highly efficient multilayer-coated blazed gratings with high fix-focus constant for the tender X-ray region. Optics Express 28 (2020), p. 821-845
Open Accesn Version

The problem of X-ray diffraction from multilayer-coated blazed diffraction gratings is analyzed. Invalidity of the conventional condition of maximal diffraction efficiency observed in previous experiments is explained theoretically. This is attributed to two factors: contribution of anti-blaze facets to diffraction efficiency and effect of strongly asymmetric diffraction. We demonstrate that a proper choice of the multilayer d-spacing allows to design grating with the diffraction efficiency close to the maximal possible one throughout the tender X-ray range (E=1-5 keV). An optimization procedure is suggested for the first time to choose the optimal grating parameters and the operation diffraction order to obtain a high fix-focus constant and high diffraction efficiency simultaneously in a wide spectral range.