The manufacturing method is described and the results of the study of the X-ray optical properties of a concave spherical mirror made of crystalline quartz are presented. The radius of curvature was 1630 mm. The shape of the mirror surface was studied on an interferometer with a diffraction wave of comparison. It was shown that in the whole processing area the maximum deviation from the nearest sphere was about 0.2 μm, and the square root of rms is 34 nm, which ensures high quality of images with an angular error of 2” (angular seconds). The reflection coefficients (about 7%) and the lower estimate of the spectral selectivity (λ / delta λ = 1775) are determined in the vicinity of the wavelength λ = 0.834 nm, which is close to the working wavelengths of the MgXII doublet (λ = 0.8418 and 0.8423 nm). During the bending of the crystal mirror, no change in the position of the Bragg peak and spectral selectivity was found within the limits of the accuracy of measurements.

The paper presents a new technique for thermoplastic bending of glass. The technique makes it possible to produce cylindrical surfaces with a guide in the form of a parabola, ellipse, etc. for mirrors in the hard X-ray wavelength range (λ~0.1 nm). Three samples of the surface of an elliptical cylinder were prepared using this technique. The production time for each sample was two days. The deviation of the guide and its local angle from the calculated values for all samples does not exceed Δy = 0.5 µm and Δα = 7*10-5 rad, respectively. It is shown that when such surfaces are etched for two hours, their accuracy can be improved by more than two orders of magnitude (Δy = 5 nm, Δα = 5*10-7 rad).