Activation cross sections, isomeric cross-section ratios and systematics of (n, 2n) reactions at 14–15 MeV

Abstract

Total cross sections for eighteen (n, 2n) reactions at 14.7 ± 0.3 MeV in the medium- and heavymass regions have been measured by the activation technique using Ge(Li) detector γ-ray spectroscopy. Isomeric (n, 2n) cross-section ratios were determined for 54Fe, 92Mo, 191Ir, 198Pt and 198Hg. A comparison of the experimental cross-section values with theoretical estimates based on the statistical model confirms that this reaction at 14–15 MeV proceeds mainly via compound nucleus formation. The dependence of the cross-section values on the relative neutron excess of the target nucleides and the systematic trends in these values are discussed in the light of the latest experimental data. No significant closed proton or neutron shell effects were discernible.