Structure in the (n, n′) Gross Sections of Se Isotopes

Abstract

Inelastic scattering of low energy neutrons can give a valuable information on statistical properties of resonance parameters. In a review given at the Conference on Nuclear Structure Study with Neutrons held in Antwerp in 1965 Ferguson [1] has discussed a few examples demonstrating the importance of width fluctuation corrections in theoretical description of average cross sections. It has been shown in a number of publications that these corrections calculated under an assumption of uncorrelated widths improved significantly an agreement of experimental results with theoretical cross sections expressed in terms of optical model transmission coefficients. In some cases, however, experimental cross sections have appeared too high compared to predictions based on the assumption of uncorrelated widths. An essential discrepancy of this kind has been observed by the authors [2,4]and by Lister and Smith [3] for the first 2+ levels of even-even isotopes of Ge. It was suggested in refs. 2–4 that large experimental cross sections observed in that case could be accounted for by channel coupling effects.