Fission cross-section measurement for the 238U(n,f)89Rb reaction induced by D-T neutrons

The fission reactions of U-238 induced by D-T neutrons were investigated by neutron activation technique and low-background HPGe-gamma spectrometer. The half-life was used to identify the possible daughter nuclide. The fission cross-sections of U-238(n,f)Rb-89 reaction induced at the neutron energy around 14 MeV, i.e., 14.1 +/- 0.3, 14.5 +/- 0.3 and 14.7 +/- 0.3 MeV, were measured precisely. The neutron flux was monitored by accompanying a-particle of the T(d,n)He-4 reaction and the neutron energies were determined by the cross-section ratio of Zr-90 (n,2n)Zr-89 to Nb-93(n,2n)(92)mNb reaction. The fission cross-sections of the U-238(n,f)Rb-89 reaction are 33.2 +/- 2.1 mb, 32.2 +/- 2.0 mb, and 32.6 +/- 2.1 mb, corresponding to the above neutron energy points.