1981 年 1 巻 2 号 p. 45-54
The attenuation and scattering of fast neutrons ranged from 0.5 to 14 MeV by various shielding materials have been studied for the purposes of design of the protective barriers and the collimators. The transmitted and scattered neutrons were measured with a conventional rem counter. The neutrons used were produced by bombarding light nuclide targets with accelerated beams of protons or deuterons using a Van de Graaff accelerator and a neutron generator. The attenuation curves for lead, iron, heavy concrete, ordinary concrete, water, paraffin and borated paraffin were determined under broad beam geometry. Scattering ratios, which were defined as the ratios of scattered neutron dose equivalent to incident neutron dose equivalent on the scatterer, were determined for the scattering angles of 45°,90° and 135° using the monoenergetic neutron beams of 0.5 to 5 MeV. The attenuation characteristics and scattering ratios obtained are tabulated in order to make it easy to use these data.
