A Compact Model for Unresolved Resonance Region Cross Sections

Abstract

For decades, the probability table technique has been used to model the behavior of neutron cross sections in the unresolved resonance region with a stochastic approach. Early work from Hwang hinted at the possibility of a universal probability distribution to fit the URR cross section distribution. In this work we present a solution to Hwang’s problem: the normal inverse Gaussian distribution fits the probabilistic behavior of the total cross section almost perfectly for the most important nuclides, both in asymptotic behavior and around the more probable regions.