Kinetic Energies of Fragments from Seven Fission Reactions at Low Excitation Energies

This work describes a double-energy experiment performed with solid-state detectors on the thermal-nuetron-induced fission of ${}_{}{}^{233}{}_{}{}^{}\mathrm{U}$, ${}_{}{}^{235}{}_{}{}^{}\mathrm{U}$, and ${}_{}{}^{239}{}_{}{}^{}\mathrm{Pu}$; fast-neutron-induced fission of ${}_{}{}^{231}{}_{}{}^{}\mathrm{Pa}$, ${}_{}{}^{237}{}_{}{}^{}\mathrm{Np}$, and ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$; and spontaneous fission of ${}_{}{}^{252}{}_{}{}^{}\mathrm{Cf}$. Spectra of the fragment masses and energies were obtained. Average total kinetic energies and mean fragment masses for the fast-neutron-induced reactions are as follows: ${}_{}{}^{231}{}_{}{}^{}\mathrm{Pa}$, 166.8±2 MeV, 92.2 and 139.8 amu; ${}_{}{}^{237}{}_{}{}^{}\mathrm{Np}$, 174.0±2 MeV, 98.0 and 140.0 amu; and ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$, 170.1±2 MeV, 98.5 and 140.5 amu. The results are compared with recent time-of-flight and radiochemical data, where available. Average total kinetic-energy correlations with $\frac{Z^2}{A^{\frac{1}{3}}}$ are shown.