On the surface shape of an X-ray monochromator

It is established that the surface of a monochromator for a point X-ray source in diffractometers is the surface of revolution of a circle arc around the straight line connecting the X-ray source and detector. It is shown that scattering occurs at the points of intersection of the monochromator surface with the set of ellipsoids of revolution, in whose focuses the X-ray source and detector are located. A formula is obtained for calculating the misorientation angle of mosaic blocks. The limits of variation in the angle for Fe \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ K_{\alpha _1 } $$\end{document}, Cu \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ K_{\alpha _1 } $$\end{document}, and Mo \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ K_{\alpha _1 } $$\end{document} radiations are determined. It is shown that there is no unified continuous reflecting monochromator surface, and the true reflecting surface is fractal.