1997 Fiscal Year Final Research Report Summary
DISSIPATIVE DYNAMICS OF HEAVY-ION FUSION-FISSION REACTION
| Project/Area Number |
08640398
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
素粒子・核・宇宙線
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| Research Institution | KONAN UNIVERSITY |
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Principal Investigator |
WADA Takahiro Konan Univ. ・ Faculty Science, Associate Professor, 理学部, 助教授 (30202419)
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| Co-Investigator(Kenkyū-buntansha) |
ABE Yasuhisa Kyoto Univ.・ YITP, Associate Professor, 基礎物理学研究所, 助教授 (80000868)
OHTA Masahisa Konan Univ. ・ Faculty Science, Professor, 理学部, 教授 (30068134)
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| Project Period (FY) |
1996 – 1997
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| Keywords | Highly Excited Compound Nucleus / Fusion-Fission Reaction / Dissipative Dynamics / Multi-Dimensional Langevin Equation / Nuclear Friction / Particle Multiplicity / Fusion Hindrance / Superheavy Element |
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| Research Abstract |
We have studied various subjects concerning the heavy-ion fusion-fission reaction from the viewpoint of dissipative dynamics.
(1) We have developed a computer code for solving a multi-dimensional Langevin equation. We have improved the interpolation routine to obtain a good performance especially on super computers. We can solve 3- and 4- dimensional Langevin equation without difficulties.
(2) We have analyzed the experimental data on the angular momentum dependence of prescission time obtained from the coincidence measurements of gamma-ray and charged particles. We have reproduced the experimentally deduced prescission time, including its angular momentum dependence.
(3) We have analyzed the phenomenon of fusion hindrance using the 2- and 3-dimensional Langevin equation. We have reproduced the experimental data for symmetric-like systems, and also calculated the systems with large mass asymmetry.
(4) We have studied the dynamical process of the synthesis of superheavy elements by dissipative dynamical models. First, we used the 1-dimensional Smoluchowski equation. Then, for a more realistic estimation, we proposed to divide the process in two stages and used 2-dimensional Langevin equation and 2-dimensional Smoluchowski equation for respective stages. We have predicted that the maximum yield is obtained around E^<**>=25MeV.
(5) We have analyzed the new data on the fission lifetime obtained with the crystal blocking method. We used the statistical model and the dissiative dynamical model.
(6) We have studied the fission of excited nuclei using the microscopic nuclear friction coefficient calculated by Dr. Yamaji, RIKEN.
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