Be/Si/Al multilayer mirrors as the most promising optical elements for spectroscopy and imaging in the spectral region of 17-32 nm

The reflective and structural parameters of Be/Si/Al multi -layer mirrors have been studied. The extent of stability of their X-ray optical characteristics has been demonstrated during storage in air for 4 years and during vacuum annealing at temperatures up to 100 degrees C. A high reflectance of 62.5% was obtained, together with a spectral selectivity of A/ increment A approximate to 59 at a wavelength of 17.14 nm and 34%, with A/ increment A approximate to 31 at a wavelength of 31.3 nm. It was shown that Si interlayers reduce the interlayer roughness from 0.45 to 0.20 nm.(c) 2023 Optica Publishing Group