Fission process of nuclei at low excitation energies with a Langevin approach
Fission process of nuclei at low excitation energies with a Langevin approach
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DOI：
10.1103/physrevc.88.044614
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发表时间：
2013-05
影响因子：
3.1
通讯作者：
Y. Aritomo;S. Chiba
中科院分区：
文献类型：
--
作者：
Y. Aritomo;S. Chiba
Fragment mass distributions from the fission of U and Pu isotopes at low excitation energies are studied using a dynamical model based on the fluctuation-dissipation theorem formulated as Langevin equations. The present calculations reproduced the overall trend of the asymmetric mass distribution without parameter adjustment for the first time using the Langevin approach. The Langevin trajectories show a complicated time evolution on the potential surface, which causes the time delay of fission, showing that dynamical treatment is vital. It was found that the shell effect of the potential energy landscape has a dominant role in determining the mass distribution, although it is rather insensitive to the strength of dissipation. Nevertheless, it is essential to include the effect of dissipation, since it has a crucial role in giving "fluctuation" to Langevin trajectories as well as for explaining the multiplicities of pre-scission neutrons as the excitation energy increases. Therefore, the present approach can serve as a basis for more refined analysis.
