Fission fragment mass yields and total kinetic energy release in neutron-induced fission of U233 from thermal energies to 40 MeV

Abstract

Properties of fission in $^{233}\mathrm{U}$ were measured at the Los Alamos Neutron Science Center at incident neutron energies from thermal to 40 MeV. Fragments were observed in coincidence by using a twin ionization chamber with Frisch grids. The average total kinetic energy released and fragment mass yields were determined by using the double energy analysis method based on conservation of mass and momentum. The experimental method was validated by using $^{232}\mathrm{Th}$ and absolute energy was calibrated by using thermal-neutron--induced fission of $^{235}\mathrm{U}$. This work incorporates novel applications of multi-chance fission channel cross sections and fission models to account for the complexities introduced by prompt neutron emission at high energy and extends results up to higher incident neutron energies than previously measured. Accurate experimental measurements of these parameters are necessary to better understand the fission process in isotopes central to the thorium fuel cycle.