The constant total-cross-section approximation and the neutron energy spectrum

The present investigation shows that under not too restrictive conditions it can be proved that the energy part and the space-angle part of the solution of the Boltzmann transport equation with the collision multiplication eigenvalue γ, can be separated provided the total cross section is constant. Furthermore, if the total cross section is constant, then the neutron energy spectrum does not depend on the size of a homogeneous system and is equal to the energy spectrum of an infinite system of the same composition. (B.G.)