Energy and angular distribution of gamma flux and dose rate behind water barriers of different thickness

The angular and energy distributions of a O.16-9.0 MeV broad gamma beam behind water barriers of different thickness (up to 450 cm) have been experimentally and theoretically studied. The experiments were performed on a research water-water reactor with the maximum power rate of 50 kW. The calculations were conducted by the Karlson method realized in the S6P6 approximation by and the KURAGA-M computer code. The total errors of the measurements were evaluated to be about 30% in the range from 0.16 MeV to 0.64 MeV and to increase to 50% at higher energies and scattering angles THETA >40 deg. The gamma spectra were found to soften with increasing energy, whereas the angular spectra-to harden with increasing thickness. As the thickness increases the shape of the angular energy spectra varies but little. The comparison of the calculated and experimental data testifies to a satisfactory agreement of the angular spectra for water thickness up to 350 cm