Introduction to the neutron transport phenomena

The behaviour of a nuclear reactor is governed by the distribution in space, energy and time of the neutrons present in the system. The neutrons present in the reactor medium interact with its nuclei and this interaction decides upon their distribution. A set of lectures has been devoted to the detailed description of the interaction processes. In the present lecture attention is focused on the neutrons overall behaviour, which is described by the neutron transport equation, often called the Boltzmann equation. The neutron transport theory is here limited to the basic phenomena necessary to understand the approach to practical solution of the problem given in the lecture on reactor lattice transport calculations. The basic definitions are introduced followed by the neutron transport equations and its approximations. The material presented is based mainly on monographs quoted in References where also a more detailed description of neutron transport phenomena can be found. (author)