Coherent excitation of X-ray fluorescence and interference of radiation at the output of polycapillary structures

The diffraction of long-wavelength X rays with the energy corresponding to the region of anomalous dispersion near the Si $L_{2,3}$ absorption edges transmitted through microchannel plates has been studied both experimentally and theoretically. The radiation of a finite antenna array, as well as the processes of excitation of X-ray fluorescence and propagation of waves in hollow waveguide structures, has been mathematically simulated. The model describes a polycapillary structure consisting of noninteracting emitters, which are hollow channels of a microchannel plate. It has been shown that coherently excited X-ray fluorescence propagates primarily in the direction of the zeroth diffraction order.