Nuclear-charge polarization at scission in proton-induced fission of U

Nishinaka, Ichiro; Tanikawa, Masashi*; Nagame, Yuichiro ; Nakahara, Hiromichi*

The most probable charges of secondary fragments in the 11.5 MeV proton-induced fission of U were determined from the mass yields measured by the double time-of-flight method and the fractional cumulative and independent yields measured radiochemically and reported in literature. The nuclear-charge polarization of primary fragments at scission was obtained by correcting the secondary fragment mass for neutron evaporation. The results show that the nuclear-charge polarization is determined by the minimum potential energy of nuclei at scission and that it is nearly independent not only of mass and excitation energy but also of the neutron-to-proton ratio of the fissioning nucleus.