Study of Heavy-ion Induced Fission for Heavy Element Synthesis

Abstract Fission fragment mass distributions were measured in heavy-ion induced fission of 238 U. The mass distributions changed drastically with incident energy. The results are explained by a change of the ratio between fusion and quasifission with nuclear orientation. A calculation based on a fluctuation dissipation model reproduced the mass distributions and their incident energy dependence. Fusion probability was determined in the analysis. Evaporation residue cross sections were calculated with a statistical model for the reactions of 30 Si+ 238 U and 34 S+ 238 U using the obtained fusion probability in the entrance channel. The results agree with the measured cross sections of 263,264 Sg and 267,268 Hs, produced by 30 Si+ 238 U and 34 S+ 238 U, respectively. It is also suggested that sub-barrier energies can be used for heavy element synthesis.