Angular momentum transfer in multinucleon transfer channels of O + Np

Tanaka, Shoya*; Hirose, Kentaro; Nishio, Katsuhisa; Kean, K. R.*; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Aritomo, Yoshihiro*

Physical Review C, 105(2), p.L021602_1 - L021602_5, 2022/02

https://doi.org/10.1103/PhysRevC.105.L021602

Origin of the dramatic change of fission mode in fermium isotope investigated using Langevin equations

Aritomo, Yoshihiro*; Miyamoto, Yuya*; Nishio, Katsuhisa

Nihon Butsuri Gakkai-Shi, 75(10), p.631 - 636, 2020/10

no abstracts in English

Effects of multichance fission on isotope dependence of fission fragment mass distributions at high energies

Tanaka, Shoya; Aritomo, Yoshihiro*; Miyamoto, Yuya*; Hirose, Kentaro; Nishio, Katsuhisa

Physical Review C, 100(6), p.064605_1 - 064605_6, 2019/12

https://doi.org/10.1103/PhysRevC.100.064605

Fission fragment mass distributions of U, Np, and Pu are studied using the Langevin approach in the widely excitation energy range as = 15-55 MeV. In the present calculation, neutron emission before fission, so called multichance fission, was introduced. The calculated results well demonstrated the experimental data, which shows the double-peak structure up to the highest excitation energies and the clear dependence on the initial fissioning nuclides. The trend is nicely correlated with the neutron binding energy of the compound nucleus that dominates the neutron emission probability before fission.

Role of multichance fission in the description of fission-fragment mass distributions at high energies

Hirose, Kentaro; Nishio, Katsuhisa; Tanaka, Shoya*; Lguillon, R.*; Makii, Hiroyuki; Nishinaka, Ichiro*; Orlandi, R.; Tsukada, Kazuaki; Smallcombe, J.*; Vermeulen, M. J.; et al.

Physical Review Letters, 119(22), p.222501_1 - 222501_6, 2017/12

https://doi.org/10.1103/PhysRevLett.119.222501

Fission-fragment mass distributions were measured for U, Np and Pu populated in the excitation-energy range from 10 to 60 MeV by multi-nucleon transfer channels in the reaction O + U at the JAEA tandem facility. Among them, the data for U and Np were observed for the first time. It was found that the mass distributions for all the studied nuclides maintain a double-humped shape up to the highest measured energy in contrast to expectations of predominantly symmetric fission due to the washing out of nuclear shell effects. From a comparison with the dynamical calculation based on the fluctuation-dissipation model, this behavior of the mass distributions was unambiguously attributed to the effect of multi-chance fission.

Study of fission using multi-nucleon transfer reactions

Nishio, Katsuhisa; Hirose, Kentaro; Lguillon, R.*; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Smallcombe, J.*; Chiba, Satoshi*; Aritomo, Yoshihiro*; Tanaka, Shoya*; et al.

Proceedings of 6th International Conference on Fission and Properties of Neutron-rich Nuclei (ICFN-6), p.590 - 597, 2017/11

https://doi.org/10.1142/9789813229426_0101

Fission fragments mass distributions of nuclei populated by the multinucleon transfer channels of the O + Th reaction

Lguillon, R.; Nishio, Katsuhisa; Hirose, Kentaro; Makii, Hiroyuki; Nishinaka, Ichiro*; Orlandi, R.; Tsukada, Kazuaki; Smallcombe, J.*; Chiba, Satoshi*; Aritomo, Yoshihiro*; et al.

Physics Letters B, 761, p.125 - 130, 2016/10

https://doi.org/10.1016/j.physletb.2016.08.010

Surrogate reactions research at JAEA/Tokyo Tech

Chiba, Satoshi; Nishio, Katsuhisa; Makii, Hiroyuki; Aritomo, Yoshihiro*; Nishinaka, Ichiro; Ishii, Tetsuro; Tsukada, Kazuaki; Asai, Masato; Furutaka, Kazuyoshi; Hashimoto, Shintaro; et al.

Nuclear Data Sheets, 119, p.229 - 232, 2014/05

https://doi.org/10.1016/j.nds.2014.08.063

Fusion probabilities in the reactions Ca + U at energies around the Coulomb barrier

Nishio, Katsuhisa; Mitsuoka, Shinichi; Nishinaka, Ichiro; Makii, Hiroyuki; Wakabayashi, Yasuo*; Ikezoe, Hiroshi; Hirose, Kentaro*; Otsuki, Tsutomu*; Aritomo, Yoshihiro*; Hofmann, S.*

Physical Review C, 86(3), p.034608_1 - 034608_6, 2012/09

https://doi.org/10.1103/PhysRevC.86.034608

Spin-dependent observables in surrogate reactions

Chiba, Satoshi; Iwamoto, Osamu; Aritomo, Yoshihiro

Physical Review C, 84(5), p.054602_1 - 054602_5, 2011/11

https://doi.org/10.1103/PhysRevC.84.054602

Observables emitted from various spin states in compound U nuclei are investigated to validate usefulness of the surrogate reaction method. It was found that energy spectrum of cascading -rays and their multiplicities, spectrum of evaporated neutrons, and mass-distribution of fission fragments show clear dependence on the spin of decaying nuclei. The present results indicate that they can be used to infer populated spin distributions which significantly affect the decay branching ratio of the compound system produced by the surrogate reactions.

Dynamical model of surrogate reactions

Aritomo, Yoshihiro; Chiba, Satoshi; Nishio, Katsuhisa

Physical Review C, 84(2), p.024602_1 - 024602_10, 2011/08

https://doi.org/10.1103/PhysRevC.84.024602

A new dynamical model is developed to describe the whole process of surrogate reactions; the transfer of several nucleons at an initial stage, thermal equilibration of residues leading to washing out of shell effects and decay of populated compound nuclei are treated in a unified framework. Multi-dimensional Langevin equations are employed to describe time-evolution of the system. The new model is capable of calculating the spin distribution of the compound nuclei, one of the most important quantities in the surrogate technique. Furthermore, observable of surrogate reactions can be calculated. It is found that spin distributions of compound nuclei produced in O+U O+U reactions are equivalent and much less than 10, therefore satisfy conditions proposed by Chiba and Iwamoto if they are used as a pair in the surrogate ratio method.