Abstract
The wide distribution in the values of the neutron widths and spacings of slow neutron levels leads to fluctuations in the cross section averaged over several levels. A method of deriving information on the properties of these distributions from observations on the fluctuations is described.
Fluctuations in total cross section measurements are analysed and agreement to order of magnitude is obtained with the predicted width and spacing distributions, but it does not appear that exact agreement is obtained at present The 235U fission cross section also is analysed by this method, but the results do not agree with the theory of the method. It is probable that these discrepancies are due to the effect of correlations in the distributions.