The basic simulation study on uranium isotope analysis through active neutron counting

A new active neutron measurement method to detect uranium isotope composition is simulated through the GEANT4 simulation toolkit. The basic principal is that the reaction cross-section for induced fission, (n, 2n) and (n, 3n) is different for different isotopes of uranium, resulting in that time-correlated coincidence neutrons are different. According to the coincidence neutrons, the isotope composition of uranium can be reached. The simulation uses two incident neutron energies that are 2.5 MeV, 14 MeV. Through the ratio of the two coincidence neutrons detected by ideal detector, the abundance of 235U can be reached. The preliminary simulation result shows that the method is feasible. (authors)