Fission decay of very light nuclear systems

Abstract

Fully-energy-damped yields from the $^{16,17,18}\mathrm{O}$${+}^{10,11}$B and $^{19}\mathrm{F}$${+}^{9}$Be reactions at ${\mathit{E}}_{\mathrm{lab}}$5 MeV/nucleon have been identified and attributed to the process of the heavy-ion fusion followed by compound-nucleus fission. The large cross sections observed for these yields while in excess of those expected based on the conventional rotating liquid drop model are nonetheless found to be consistent with calculations using fission barrier energies more appropriate for light systems. An alternative explanation of the observed yields, based on the formation of a dinucleus orbiting complex, fails to account for the experimental results. This work offers the most compelling evidence yet obtained of the occurrence of fission process in light, s-d shell nuclei.