Systematic behavior of fission fragment mass distribution for nuclei populated by multi-nucleon transfer reactions

Lguillon, R.; 西尾 勝久   ; 廣瀬 健太郎  ; 牧井 宏之   ; 西中 一朗; Orlandi, R.  ; 石井 哲朗  ; 塚田 和明  ; 有友 嘉浩*; 千葉 敏*; 大槻 勤*

Lguillon, R.; Nishio, Katsuhisa; Hirose, Kentaro; Makii, Hiroyuki; Nishinaka, Ichiro; Orlandi, R.; Ishii, Tetsuro; Tsukada, Kazuaki; Aritomo, Yoshihiro*; Chiba, Satoshi*; Otsuki, Tsutomu*

We are promoting a campaign to measure the mass distributions of fission fragments and their excitation energy dependence for a large set of actinide nuclei populated by multi-nucleon transfer reactions. The results obtained in the reaction O + Th will be presented. Multi-nucleon transfer reaction allows us to produce wide variety of compound nuclei including neutron-rich nuclei, which cannot be accessed by fusion reaction. Unique feature in this approach in this fission study is that we can populate the fissioning nuclei from its ground state up to excitation energy of several tens MeV. We thus obtain the excitation energy dependence of the mass distribution. Also, more than 10 nuclei can be investigated in a single experiment, allowing us to test the universal behavior of input parameters of the model calculations. The experiment was carried out at the 20MV JAEA tandem facility at Tokai. Transfer-channels and excitation energies of the fissioning nuclei were identified using silicon dE-E detectors located to the forward direction of the Th target. Two fission fragments were detected in coincidence using multi-wire proportional counters. Fission fragment masses were determined by kinematic consideration. The experimental data include those for Ac, Th and Pa obtained for the first time.