High-Energy Neutron Concentration Far from a Source

Abstract

The concentration of neutron radiation far from a source is discussed. A new method is proposed for solving this problem by choosing from among the scattered neutrons the ones that have acquired the required direction of flight and energy. The material along which such a neutron will travel must possess a small neutron cross section at the given energy. Materials consisting of isotopes with a large resonance cross section, for example, ⁵⁶Fe, meet the requirements. The method discussed for concentrating high-energy neutrons makes it possible to increase their concentration more than 1000-fold in the detection area far from the source compared with isotropic propagation away from the source in all directions with equal probability.