Effect of multiple spin species on spherical shell neutron transmission analysis

Abstract

A series of Monte Carlo calculations have been performed in order to evaluate the effect of separated vs merged spin statistics on the analysis of spherical shell neutron transmission experiments for gold. It is shown that the use of separated spin statistics consistently results in larger average capture cross sections of gold at 24 keV. This effect is explained by stronger windows in the total cross section caused by the interference between potential and J₊ resonances and by J₊ and J₋ resonance overlap allowed by the use of separated spin statistics. Using the latest published separated spin statistics, the value of the average capture cross section for gold at 24 keV is 710 ± 25 mbarn.