Spectral characteristics of plane multilayer amplitude diffraction gratings for the soft x-ray range

Several spectral characteristics of plane multilayer amplitude molybdenum – silicon diffraction gratings (1000 and 2000 lines mm^–1), fabricated by electron-beam lithography, were determined with a broadband laser-plasma source of soft x-rays. The gratings, with the multilayer structure period 11.5 nm, were investigated at near-normal incidence and at an angle of incidence of 36° in a quasi-stigmatic spectrograph system with moderate dispersion. The spectral profile of resonant reflection by the gratings was determined in the first and second interference orders of the multilayer structure for different angles of incidence. The line spectrum of multiply charged F(V) and F(VI) ions was recorded in the 16.0 — 18.5 nm range by means of these multilayer gratings and the resolving power of the gratings was estimated.