Total (n, 2n) cross sections and isomeric cross-section ratios at 14.7 MeV in the region of rare earths

Abstract

Total cross sections for (n, 2n) reactions at 14.7 ± 0.3 MeV on twenty-nine stable nucleides of the elements cerium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and hafnium have been measured by the activation technique using Ge(Li) detector γ-ray spectroscopy. Isomeric (n, 2n) cross-section ratios have been determined for the isomeric pairs 137m, gCe, 139m, gCe, 141m, gNd, 143m, gSm, 150m, gEu, 152m 2, g Eu, 152m 1, g Eu, 158m, gTb, 164m, gHo and 174m, gLu. A comparison of the experimental cross-section values with theoretical estimates based on the statistical model confirms that the (n, 2n) reaction at this energy in the rare-earth region proceeds mainly via compound nucleus formation and accounts for > 80% of the total inelastic cross section.