Normal-incidence Sb/B4C multilayer mirrors for the 80 Å < λ < 120 Å wavelength range

Periodic and aperiodic Sb/B4C multilayer structures have been theoretically calculated and synthesised for the first time for the application in soft X-ray optics in the 80 Å < λ < 120 Å range. The reflection spectra of the periodic multilayer mirrors are measured using synchrotron radiation and laser plasma-generated radiation. The experimental spectra are theoretically interpreted with the inclusion of transition layers and substrate roughness. The density of antimony layers is supposedly ρ_(Sb) = 6.0 g cm^-3, and the thickness of transition layers (if any) in the Sb/B4C multilayer structures does not exceed 10 Å. A peak reflectivity of 19 % is attained at a wavelength of 85 Å. An aperiodic mirror optimised for maximum uniform reflectivity in the 100 – 120 Å range is tested employing the laser plasma radiation source.