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Abstract
The leakage neutron spectra measurements have been done on benchmark spherical assembly-nickel sphere with diameter of 50 cm and copper cube with an edge of 48.4 cm. The Cf-252 neutron source was placed into the centre of nickel sphere and copper cube. The proton recoil method was used for neutron spectra measurement using spherical hydrogen proportional detectors (HPD) with pressure of 400 and 1000 kPa (diameter of detectors is 4 cm) and using scintillation stilbene detector (diam. 1x1 cm). The neutron energy range of spectrometer is 0.06-1.3MeV for HPD (HPD region) and 1-10MeV for stilbene (stilbene region). The adequate MCNP neutron spectra calculations based on data libraries ENDF/B-VII.1, ENDF/B-VIII.0, JEFF-3.3, BROND-3.1 and ROSFOND-2010 were done. The neutron energy structure used for calculations and measurements was 40 and 200 groups per decade (gpd) and step of 100 keV for stilbene. Structure 200 gpd represents lethargy step about of 1%.