The effect of sapphire and bismuth single-crystal filters and their combinations on the quality of neutron
radiographic images and neutron tomography data has been studied. The parameters of the contrast
of the neutron image were analyzed depending on the monocrystalline filters. Neutron transmission
spectra were obtained for sapphire and bismuth single crystals. Additionally, the effect of filters on
the overall intensity of the thermal neutron beam and the background of gamma-rays was investigated.
Based on the obtained data, we assume that a single-crystal sapphire filter can be most effectively used
for radiographic and tomographic installations using thermal neutrons.