Fission cross-section measurements for the U(n,f)Nb, U(n,f)Te and U(n,f)Sb reactions induced by D-T neutrons.

In this study, we conducted measurements of the independent fission cross-sections of U(n, f)Nb, U(n, f)Te reactions and the cumulative cross section of U(n, f)Sb reactions induced by neutron at energies around 14 MeV, i.e., 14.1 ± 0.3, 14.5 ± 0.3 and 14.7 ± 0.3 MeV. The measurement results were obtained by the neutron activation method in combination with off-line γ-ray spectrometry techniques. The neutron flux was monitored on line by the accompanying α-particle from T(d, n)He reaction, and the neutron energies were determined by the cross-section ratio of Zr(n, 2n)Zr to Nb(n, 2n)Nb reactions. The independent fission cross-sections of the fission reactions were obtained by subtracting the influence of precursor nuclei or excited states. The obtained results are as follows: for U(n, f)Nb, the independent cross sections are 1.0 ± 0.89, 0.98 ± 0.85 and 0.78 ± 0.70 mb at the specified neutron energy points. For U(n, f)Te, the independent fission cross-sections are 26.8 ± 2.8, 27.7 ± 2.9 and 20.5 ± 2.3 mb, respectively, at the same neutron energy points. As for (n, f)Sb, the obtained cumulative fission cross-sections are 5.35 ± 0.58, 5.05 ± 0.53 and 4.03 ± 0.44 mb, respectively, at the specified neutron energy points.