The Behavior of Extrapolation Distances in Die-Away Experiments

Multigroup extrapolation distances have been computed, both in P₃ and diffusion theory, for a number of pulsed moderator systems. Factors which determine the extrapolation distance can be conveniently classified as “multigroup” or “transport” effects. Apparently these effects are separable. Multigroup effects may be treated, with good accuracy in diffusion theory, while a one-group model suffices for the analysis of transport effects.