Cross sections of the 143Nd(n,α)140Ce and 147Sm(n,α)144Nd reactions in the MeV neutron energy region

Cross sections and forward/backward ratios in the laboratory reference system were measured for the 143Nd(n,α)140Ce reaction at 4.0, 5.0, and 6.0 MeV and for the 147Sm(n,α)144Nd reaction at 5.0 and 6.0 MeV. A twin-gridded ionization chamber and large-area back-to-back 143Nd2O3 samples and 147Sm2O3 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 2H(d,n)3He reaction by using a deuterium gas target. A small 238U fission chamber was employed for absolute neutron flux determination, and a BF3 long counter was used as the neutron flux monitor. Present experimental data are compared with previous measurements, evaluations, and model calculations.