Nuclear Fission in Low Excitation Energy within Macroscopic-microscopic Model and Langevin Approach

被引：0

作者：

Liu L. ^{[1
]}

Chen Y. ^{[1
]}

Wu X. ^{[2
]}

Li Z. ^{[2
]}

Ge Z. ^{[1
]}

Shen C. ^{[3
]}

Su Y. ^{[1
]}

Huang X. ^{[1
]}

Shu N. ^{[1
]}

机构：

[1] China Nuclear Data Center, Key Laboratory of Nuclear Data, China Institute of Atomic Energy, Beijing

[2] Department of Nuclear Physics, China Institute of Atomic Energy, Beijing

[3] Huzhou University, Huzhou

来源：

Yuanzineng Kexue Jishu/Atomic Energy Science and Technology | 2022年 / 56卷 / 05期

关键词：

Fission fragment mass distribution; Langevin model; Macroscopic-microscopic model; Total kinetic energy distribution;

D O I：

10.7538/yzk.2022.youxian.0127

中图分类号：

学科分类号：

摘要：

The three-dimensional Langevin model was used to study the fragment mass distribution and total kinetic energy (TKE) distribution and the scission configuration in low-energy nuclear fission, in which the potential energy surface was calculated by using the macroscopic-microscopic model based on the two-center shell model and the finite range liquid drop model, and the inertia tensor and the friction tensor were obtained within the Werner-Wheeler method and the wall-and-window model, respectively. Taking the case of 14 MeV n+235U fission as an example, the influence of the elongation deformation space on the fission fragment mass distribution and the TKE distribution was investigated, and the correlation between the elongation and the mass asymmetry at the scission point was also studied. It is found that the elongation deformation space has a significant influence on the symmetric fission channel, especially for the calculation of the TKE around the symmetric mass region, which is because that the symmetric channel corresponds to the super-long deformation for the light actinide nuclei such as U, Np, Pu and so on, so that the less elongation deformation space could block the larger elongated nuclear shapes along the Langevin trajectories. In addition, the influence of the shell damping parameter on the fission fragment mass distribution and TKE distribution and the scission configuration was studied. It is found that the shell damping parameter has a larger influence on the fragment mass distribution, and the ratio of the peak height and the valley increases with the larger shell damping parameter, due to the stronger shell effect. However, it has little influence on the TKE distribution which indicates that the strength of the shell effect has little influence on the nuclear elongation. In the last, the pre-neutron and post-neutron fragment mass distributions for the 14 MeV n+233, 235U fission were calculated, and the results agree well with the evaluated data from ENDF/B-Ⅷ.0, which shows that the present model has the power of calculating the fission fragment mass distribution quantitatively. © 2022, Editorial Board of Atomic Energy Science and Technology. All right reserved.

引用

页码：879 / 887

页数：8

共 32 条

[1] BROSA U, GROSSMANN S, MuLLER A., Nuclear scission, Phys Rep, 197, 4, pp. 167-262, (1990)
[2] SCHMIDT K H, JURADO B, AMOUROUXB C, Et al., General description of fission observables: GEF model code, Nucl Data Sheets, 131, pp. 107-221, (2016)
[3] WILKINS B D, STEINBERG E P, CHASMAN R R., Scission-point model of nuclear fission based on deformed-shell effects, Phys Rev C, 14, 5, (1976)
[4] PASCA H, ANDREEV A V, ADAMIANET G G, Et al., Possible origin of transition from symmetric to asymmetric fission, Phys Lett B, 760, pp. 800-806, (2016)
[5] ARITOMO Y, CHIBA S, IVANYUK F., Fission dynamics at low excitation energy, Phys Rev C, 90, (2014)
[6] USANG M D, IVANYUK F A, ISHIZUKA C, Et al., Analysis of the total kinetic energy of fission fragments with the Langevin equation, Phys Rev C, 96, (2017)
[7] ISHIZUKA C, USANG M D, IVANYUK F A, Et al., Four-dimensional Langevin approach to low-energy nuclear fission of <sup>236</sup>U, Phys Rev C, 96, (2017)
[8] SIERK A J., Langevin model of low-energy fission, Phys Rev C, 96, (2017)
[9] KOSTRYUKOV P V, DOBROWOLSKI A, NERLO-POMORSKA B, Et al., Potential energy surfaces and fission fragment mass yields of even-even superheavy nuclei, Chin Phys C, 45, 12, (2021)
[10] RANDRUP J, MOLLER P., Brownian shape motion on five-dimensional potential-energy surfaces: Nuclear fission-fragment mass distributions, Phys Rev Lett, 106, (2011)

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