Binary structure in time distributions of fission fragments in 13-MeV proton-induced fission of Th232

In the proton-induced fission of $^{232}\mathrm{Th}$, a binary structure was observed in the velocity and the total-kinetic-energy distributions of fission fragments with A=128--131. From the present results, it is concluded that there are at least two kinds of scission configurations: elongated shapes probably associated with the symmetric liquid-drop path, and more compact shapes associated with the asymmetric shell-influenced path.