Measurement of fission cross section for 232Th (n,f) 131 ZX ( Z = 50 , 51, 52, 53) reaction induced by neutrons around 14 MeV

Abstract

The fission cross sections of 232Th (n,f) 131m, gSn , 232Th (n,f) 131Sb , 232Th (n,f) 131m, gTe , 232Th (n,f) 131I fission reactions induced by 14MeV neutrons were measured precisely with the neutron activation technique. The neutron flux was monitored by accompanying $ \alpha$ particle in the irradiation and the neutron energies were determined by the cross section ratio of 90Zr (n,2n) 89Zr to 93Nb (n,2n) 92mNb reaction. The values of the cross sections of 232Th (n,f) 131m, gSn were analyzed, and the cross sections of 232Th (n,f) 131Sb were deduced to be $ 6.5\pm 0.7$ , $ 6.3\pm 0.6$ , $ 6.1\pm 0.6$ mb at $ 14.1\pm 0.3$ , $ 14.5\pm 0.3$ and $ 14.8\pm 0.3$ MeV, respectively. The values of the cross sections of 232Th (n,f) 131gTe were deduced to be $ 1.8\pm 0.1$ , $ 1.5\pm 0.1$ and $ 1.4\pm 0.1$ mb at $ 14.1\pm 0.3$ , $ 14.5\pm 0.3$ and $ 14.8\pm 0.3$ MeV, respectively. The values of the cross sections of 232Th (n,f) 131I were given as $ 1.8\pm 0.2$ , $ 1.6\pm 0.2$ , $ 1.5\pm 0.1$ mb at $ 14.1\pm 0.3$ , $ 14.5\pm 0.3$ and $ 14.8\pm 0.3$ MeV, respectively.