Analysis of temporal and spatial decay of pulsed neutrons in single- and multiple-core systems

To gain insight into the space-time kinetics of coupled core systems, a series of simple one-dimensional model solutions were investigated. The spatial and temporal decay of a plane pulse was calculated in one- and three-region systems with one- and two-group diffusion theory. The solution technique consisted of a temporal Laplace transform, analytical solution for the space dependence and finally a numerical inverse Laplace transform back to time domain. The space-time behaviour of the pulse relaxation in many-region systems has been used to support the development and verification of lumped (many-point) coupled core models