Low-Energy Charged-Particle-Induced Fission

The excitation functions for the proton and deuteron induced fission of ${\mathrm{Th}}^{232}$ and ${\mathrm{U}}^{238}$ have been determined in the energy range of 3-12 MeV. The excitation functions were measured using direct counting with $p$, $n$ junction counters, gross counting with a recoil catching technique, and radiochemical measurement of certain fission product nuclides. In addition, the ratio of the peak-to-valley values of the fission-fragment kinetic-energy spectrum were determined as a function of bombarding energy. Breaks in the ratio curve at certain bombarding energies are interpreted in terms of competition between fission and nucleon evaporation.