Systematics of charge distribution studies in low-energy fission of actinides

Charge distribution studies were carried out in the thermal neutron-induced fission of Th-229, Pu-241 and Cm-245 as well as in the spontaneous fission of Cf-252. The width parameter (sigma(Z)/sigma(A)), the most probable charge/mass (Z(P)/A(P)) and the charge polarization (Delta Z) as a function of fragment mass were deduced. The slope of charge polarization as a function of fragment mass [delta(Delta Z)/delta A'], average charge dispersion parameter ([sigma(Z)]) and proton odd-even effect (delta(P)) were also obtained for these fissioning systems. These data along with the literature data for even-Z fissioning systems such as Th-233*, U-233*, U-234*, U-236*, U-239*, Pu-239*, Pu-240* and Cf-250* are discussed in terms of nuclear-structure effects and dynamics of descent from saddle point to the point of neck formation and from the formation of the neck to the scission point.