Anisotropy of diffraction characteristics of thin pyrolytic graphite films

We have studied polar diagrams and local diffraction characteristics of thin highly oriented pyrolytic graphite (HOPG) films used for X-ray monochromatization and spectrometry. The measurements have been performed on a two-wave X-ray reflectometer. The angular azimuthal scanning of initial HOPG films by a probe with a cross section below 0.1 mm$^2$; the diffraction reflection coefficient exhibited a sharp anisotropy. It is shown that the effect of anisotropy can be suppressed and an HOPG film can be used as a dispersive element for X-ray tomography and mapping, as well as for studying spectra with a single pulse of an X-ray laser.