Cross sections of theNd143(n,α)Ce140andSm147(n,α)Nd144reactions in the MeV neutron energy region

Abstract

Cross sections and forward/backward ratios in the laboratory reference system were measured for the $^{143}\mathrm{Nd}(n,\ensuremath{\alpha})^{140}\mathrm{Ce}$ reaction at 4.0, 5.0, and 6.0 MeV and for the $^{147}\mathrm{Sm}(n,\ensuremath{\alpha})^{144}\mathrm{Nd}$ reaction at 5.0 and 6.0 MeV. A twin-gridded ionization chamber and large-area back-to-back $^{143}\mathrm{Nd}{}_{2}{\mathrm{O}}_{3}$ samples and $^{147}\mathrm{Sm}{}_{2}{\mathrm{O}}_{3}$ samples were employed. Experiments were performed at the 4.5 MV Van de Graaff accelerator of Peking University, China. Fast neutrons were produced through the $^{2}\mathrm{H}(d,n)^{3}\mathrm{He}$ reaction by using a deuterium gas target. A small $^{238}\mathrm{U}$ fission chamber was employed for absolute neutron flux determination, and a ${\mathrm{BF}}_{3}$ long counter was used as the neutron flux monitor. Present experimental data are compared with previous measurements, evaluations, and model calculations.