BIMODAL NATURE OF ACTINIDE FISSION

Mass and kinetic energy distributions have been measured in the proton -induced fission of Th-232 and U-238 With two time-of-flight counter t elescopes in coincidence. A binary structure was observed in the veloc ity and total kinetic energy distributions of fission fragments, with A = 128-131 for Th-232+p fission and A = 128-130 for U-238+p fission. From the present results, it is concluded that there are at least two kinds of scission configuration: elongated shapes probably associated with the symmetric path, and more compact shapes associated with the a symmetric path.