The theory of axial tomography based on the inverse Radon transform for high-aperture soft X-ray microscopy

For soft X-ray microscopy in the approximation of geometrical optics, a theoretical model for the formation of the received image is constructed - a relationship is found between the image recorded on the detector and the 3$D$ distribution of the sample absorption index using a high-aperture mirror objective (NA > 0.3) with a focus depth close to the diffraction limit. The solution of the inverse problem of tomography for determining this 3$D$ distribution from the data of measurements in a high-aperture mirror SXR-microscope is obtained.