Fission study of actinide nuclei using multi-nucleon transfer reactions

多核子移行反応を用いたアクチノイド原子核の核分裂研究

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 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 excited states of compound nucleus from its ground state up to several tens MeV. We thus obtain the excitation energy dependence of the mass distributions. The experiment was carried out at the 20 MV JAEA tandem facility at Tokai. Transfer-channels and excitation energies of the fissioning nuclei were identified using silicon E-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.