Fission Excitation Functions for Charged Particles

Abstract

Absolute fission excitation functions have been measured with an ionization chamber to detect the pulse of a recoiling single fragment. In the experiment performed, the 60-in. Crocker cyclotron deuterons and alpha-particles were used with ${\mathrm{Th}}^{232}$, ${\mathrm{U}}^{235}$, and ${\mathrm{U}}^{238}$ targets. Thresholds of these reactions were also observed. The maximum alpha-particle energy used was 33.5 Mev and the maximum deuteron energy was 17.5 Mev. Beam current was integrated with a Faraday cup and an ionization chamber.The 184-in. synchrocyclotron was used to extend the fission excitation functions to alpha-particle energies of 390 Mev and deuteron energies of 193 Mev. ${\mathrm{Bi}}^{209}$ and ${\mathrm{Au}}^{197}$ targets were also added. Preliminary results with protons of 340 Mev maximum energy are also reported.The results of the experiments are summarized in Figs. 3 to 17 inclusive.