Total excitation energy and neutron multiplicity of fission fragments for uranium isotopes

Abstract

The total excitation energy, TXE, as a function of fission fragments, is evaluated for neutron-driven fission of 230-236U using the statistical scission point model. In this model, as the systematic model, the total excitation energy includes the deformation and intrinsic energy. TXE values calculated by the systematic model are compared with the available experimental data for the neutron-induced 233U. Then the total excitation energy as a function of fission fragments is evaluated for neutron-induced fission of 230-236U. The total excitation energy distribution is compared for neutron-induced fission and for photofission of 233U and 238U. There is little difference between the TXE distribution of neutron-induced fission and photofission. The prompt neutron distribution is evaluated by using the obtained total excitation energy. The calculated prompt neutron number has a large variation for even uranium isotopes due to the neutron-separated energy of fission fragments. In addition, the prompt neutron number for heavy fission fragments is less than the experimental neutron number which due to the excess neutron of those fragments. It is due to the evaporation of an excess neutron with lower TXE values in heavy fragments.

Keywords

• total excitation energy
• fission fragments
• neutron-induced fission
• neutron number