The Statistical Estimation of Thermal-Neutron Cross Sections

The thermal radiative capture cross sections of 87 nuclides were computed using a Monte Carlo selection of reduced neutron widths, and the assumption that distant resonance levels determine the cross section. Histograms of possible cross-section values were prepared for each nuclide, and the 87 samples analyzed to find the overall accuracy of estimation. The results indicated a fluctuation of 0.4 ± 0.6 for the logarithm of the ratio of experiment to the calculated mean cross section. Tables of results for means and standard deviations are given together with the results of Keane's summation formula. The possible use of this technique in estimating unknown cross sections is discussed.