Measurement of fission-fragment mass distributions in the multinucleon transfer channels of the O+Np reaction

Vermeulen, M. J.; Nishio, Katsuhisa; Hirose, Kentaro; Kean, K. R.; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Tsekhanovich, I.*; Andreyev, A. N.; Ishizaki, Shoma*; et al.

Physical Review C, 102(5), p.054610_1 - 054610_11, 2020/11

https://doi.org/10.1103/PhysRevC.102.054610

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

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

Physical Review C, 99(5), p.051601_1 - 051601_7, 2019/05

https://doi.org/10.1103/PhysRevC.99.051601

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

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

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

no journal, , 

Recently, fission-fragment mass distributions (FFMDs) were measured for U, Np, and Pu populated in the excitation-energy range from 10 to 60 MeV by multinucleon transfer channels in the reaction O + U at the Japan Atomic Energy Agency tandem facility. A persistence of predominantly asymmetric FFMDs was observed up to the highest measured excitation energy for all the studied nuclides. To understand this behavior, we use the fluctuation-dissipation model and employ Langevin equations to obtain FFMDs and clarify multichance fission (MCF) effects. FFMDs are calculated for twenty-nine compound nuclides Th, Pa, U, Np and Pu with the excitation energy range from 15 to 55 MeV. The calculation results show generally good agreement with experimental data. It was shown that a reliable understanding of the observed FFMDs can be obtained only by invoking MCF.

Theoretical study of nuclear fission using multi-nucleon transfer reaction

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

no journal, , 

no abstracts in English

Study of fission fragment angular distribution in heavy-ion multi-nucleon transfer reaction

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

no journal, , 

Using heavy-ion fusion reactions, elements up to Z = 118 have been successfully synthesized so far. Two different experimental approaches have been employed, the cold (Pb,Bi-based) and the hot (actinide targets based) fusion reactions. It is evident, however, that fusion reactions using stable beam and available target nuclei do not allow us to reach the center of island of stability due to the insufficient neutrons introduced to the compound nucleus. Recently, heavy-ion multi-nucleon transfer (MNT) reaction is expected as unique reaction which allows us to populate neutron-rich nuclei. Due to the complexity of the MNT reactions, its reaction mechanism is not well understood, making the cross-section estimation to produce neutron-rich SHE difficult. Among the several properties to be solved, the purpose of this study is to remove the uncertainty of angular momentum of compound nucleus produced by MNT reaction. From the preliminary analysis using the experimental data, it is implied that angular momentum of the compound nucleus increases linearly with the number of transferred nucleons from the projectile to the target nucleus.

Measurement of fission-fragment mass distributions in the multinucleon transfer channels of the O+Np reaction

Nishio, Katsuhisa; Vermeulen, M. J.*; Hirose, Kentaro; Kean, K. R.*; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Tsekhanovich, I.*; Andreyev, A. N.; Ishizaki, Shoma*; et al.

no journal, , 

no abstracts in English

Fission experiment using Es-254 at JAEA Tokai tandem accelerator facility

Hirose, Kentaro; Nishio, Katsuhisa; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Asai, Masato; Sato, Tetsuya; Ito, Yuta; Suzaki, Fumi; Nagame, Yuichiro*; et al.

no journal, , 

A specific phenomenon was found in fission-fragment mass distributions for nuclides around A=258 by spontaneous fission measurements. Fm256 splits into light and heavy fragments, like uranium isotopes, making two peaks in their mass distribution, whereas a sharp single peak was found in that of Fm258 which has only two more neutrons. In order to study such a specific phenomenon more widely, we performed an experiment of the multinucleon transfer fission in the O18+Es254 reaction at JAEA Tokai tandem accelerator facility.

Fission of Md produced in the He + Es reaction

Nishio, Katsuhisa; Hirose, Kentaro; Makii, Hiroyuki; Orlandi, R.; Kean, K. R.*; Tsukada, Kazuaki; Toyoshima, Atsushi*; Asai, Masato; Sato, Tetsuya; Chiera, N. M.*; et al.

no journal, , 

no abstracts in English