The fully energy-damped cross sections of the ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$${+}^{24}$Mg reaction at ${\mathit{E}}_{\mathrm{c}.\mathrm{m}.\mathrm{}}$=44.4 MeV have been measured for all of the major fission channels. High-resolution Q-value spectra have been obtained for the large-angle yields in the ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$${+}^{24}$Mg and ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$${+}^{28}$Si channels. Calculations based on the transition-state model are found to reproduce the fully damped cross sections in all of the observed mass channels. The pronounced structure that is observed in the excitation-energy spectra for the more symmetric mass channels, even for the strongly damped yields, is shown to be qualitatively reproduced by assuming a spin-weighted population of the fragment states. There is no evidence, however, that the structure of the nascent fission fragments at scission may influence the population of states in the fragments. These results, taken together with earlier measurements of the resonance behavior of this system, suggest the coexistence of fission from the normal, compact compound nucleus with that from the deformed configurations believed to be responsible for the resonance behavior.

• Received 8 October 1993

DOI:https://doi.org/10.1103/PhysRevC.49.1031