TY - JOUR
T1 - Role of Multichance Fission in the Description of Fission-Fragment Mass Distributions at High Energies
AU - Hirose, K.
AU - Nishio, K.
AU - Tanaka, S.
AU - Léguillon, R.
AU - Makii, H.
AU - Nishinaka, I.
AU - Orlandi, R.
AU - Tsukada, K.
AU - Smallcombe, J.
AU - Vermeulen, M. J.
AU - Chiba, S.
AU - Aritomo, Y.
AU - Ohtsuki, T.
AU - Nakano, K.
AU - Araki, S.
AU - Watanabe, Y.
AU - Tatsuzawa, R.
AU - Takaki, N.
AU - Tamura, N.
AU - Goto, S.
AU - Tsekhanovich, I.
AU - Andreyev, A. N.
N1 - Funding Information:
The authors would like to thank the crew of the JAEA-tandem accelerator facility for their beam operation. Present study is supported by “Comprehensive study of delayed-neutron yields for accurate evaluation of kinetics of high burn-up reactors” and “Development of prompt-neutron measurement in fission by surrogate reaction method and evaluation of neutron-energy spectra” by the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT). This work was partly done within an IAEA CRP on beta-delayed neutrons (F41030). The Langevin calculations have been done using the cluster computer system (Kindai-VOSTOK) which is supported by “Research funds for External Fund Introduction” by Kindai University. This work was also supported partly by STFC of the United Kingdom.
Publisher Copyright:
© 2017 American Physical Society.
PY - 2017/11/27
Y1 - 2017/11/27
N2 - Fission-fragment mass distributions were measured for U237-240, Np239-242, and Pu241-244 populated in the excitation-energy range from 10 to 60 MeV by multinucleon transfer channels in the reaction O18+U238 at the Japan Atomic Energy Agency tandem facility. Among them, the data for U240 and Np240,241,242 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 multichance fission.
AB - Fission-fragment mass distributions were measured for U237-240, Np239-242, and Pu241-244 populated in the excitation-energy range from 10 to 60 MeV by multinucleon transfer channels in the reaction O18+U238 at the Japan Atomic Energy Agency tandem facility. Among them, the data for U240 and Np240,241,242 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 multichance fission.
UR - http://www.scopus.com/inward/record.url?scp=85037694900&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85037694900&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.119.222501
DO - 10.1103/PhysRevLett.119.222501
M3 - Article
C2 - 29286806
AN - SCOPUS:85037694900
SN - 0031-9007
VL - 119
JO - Physical Review Letters
JF - Physical Review Letters
IS - 22
M1 - 222501
ER -