Fabrication and investigation of imaging normal-incidence multilayer mirrors with a narrow-band reflection in the range λ ≅ 4.5 nm

Soft X-ray spherical normal-incidence mirrors (D = 60 mm, r = 2000 mm) with metal-carbon multilayer coatings, which provide a narrow-band reflection in the spectral range λ approximately 4.5 nm, have been synthesized using the pulsed laser deposition technique. The peak reflectivity of the multilayers reaches 13%, and the wavelength-to-bandwidth ratio λ/Δλ approximately 80. The spectral characteristics of the mirrors and their aperture uniformity have been evaluated using a broadband laser-plasma XUV radiation source. Discussed briefly are the applications to the investigation of complex spectra of broad-band sources (the Sun, laser-produced plasma, etc.) employing telescopes for X-ray astronomy and stigmatic high-resolution laboratory spectrometers.