Approximate formulae for the calculation of effective resonance integrals in the statistical region

Approximate formulae are given for calculating values of the function J(ξ, β) averaged over the Porter-Thomas distribution of reduced neutron widths, so that effective resonance integrals can be calculated in the statistical region. A method of error correction is suggested. In the case of infinitely dilute resonance integrals, averaging over the Porter-Thomas distribution and integration over energy can be carried out explicitly, if it is assumed that in the statistical region resonances have a uniform spacing equal to the mean of the statistical distribution of spacing. (author)