Study of fission using multi-nucleon transfer reactions

多核子移行反応を用いた核分裂過程の研究

西尾 勝久   ; 廣瀬 健太郎  ; Lguillon, R.*; 牧井 宏之   ; Orlandi, R.  ; 塚田 和明  ; Smallcombe, J.*; 千葉 敏*; 有友 嘉浩*; 田中 翔也*; 大槻 勤*; Tsekhanovich, I.*; Petrache, C. M.*; Andreyev, A. N.

Nishio, Katsuhisa; Hirose, Kentaro; Lguillon, R.*; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Smallcombe, J.*; Chiba, Satoshi*; Aritomo, Yoshihiro*; Tanaka, Shoya*; Otsuki, Tsutomu*; Tsekhanovich, I.*; Petrache, C. M.*; Andreyev, A. N.

We are promoting a fission study using multi-nucleon transfer reactions, where excited states in neutron-rich actinide nuclei, which cannot be accessed by particle capture and/or fusion reactions, are populated. This allows us to study fission in the new region of chart of nuclei. Also, the excited states in the fissioning nucleus are widely populated in the reactions, thus the effects of excitation energy on fission can be investigated. Experiments were carried out at the JAEA tandem facility in Tokai, Japan. We studied reactions using the O beam (9MeV/u) and several actinide target nuclei such as Th, U, Np, Cm. Ejectile nuclei and thus the transfer channels were identified by a newly developed silicon E-E detectors. The produced nuclei in one experiment reached more than fifteen. Fission fragment mass distributions (FFMDs) were measured for each isotopes. Measured FFMDs are reproduced by a calculation based on the fluctuation-dissipation model (Langevin-type calculation), where effects of multi-chance fission were included. We also started to measure the prompt neutrons accompanied by fission.