A Comparison Between Neutron Waves Reflected from the Reflector and from the Core of a Water-Moderated and -Reflected Reactor

When a propagating neutron wave reaches an interface between two media, a part of it is transmitted and a part is reflected. In the present work, neutron waves reflected from the core and from the reflector are compared. The following is concluded: Reflection exists in both cases. When the first medium in which the wave is propagating is a multiplying medium, it is much easier to detect the reflected wave than it is in the nonmultiplying diffusive medium. The reflected wave amplitude and phase depend much more on the properties of the first medium than on the properties of the reflecting medium. Neutron waves reflected back into the core are in phase with the propagating waves and hence reinforce them. Neutron waves reflected by the core are out of phase with the propagating waves and hence weaken them. Other characteristics of the amplitudes and phases of waves in both cases are compared.