ABSTRACT
The measurements of iron, beryllium and carbon sphere neutron leakage spectra using BC501A detector by DT neutron source are presented. The experiments were carried out in Institute of Nuclear Physics and Chemistry (INPC), China. Neutron leakage spectra in a wide energy range at angles of 0° and 30° from the direction of incident deuteron beam were obtained. The results show the leakage neutron flux decreases notably with the spherical shell increasing when neutron energy >10MeV. When neutron energy <6MeV the leakage neutron distribution tends to lower energy side with the shell increase. The total uncertainty evaluation of the neutron spectra is also provided: in the high-energy parts the uncertainty is about 5-7%, while in the low-energy parts the uncertainty is about 7-9%. In order to compare the experiment results a Monte-carlo calculation was made using the MCNP5 Code with the ENDF/B-VII.1 nuclear data files.