Project/Area Number |
11680486
|
Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
プラズマ理工学
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Research Institution | Osaka University |
Principal Investigator |
NISHIHARA Katsunobu Institute of Laser Engineering, Osaka University, Professor, レーザー核融合研究センター, 教授 (40107131)
|
Co-Investigator(Kenkyū-buntansha) |
SAKAGAMI Hitoshi Institute of Himeji Technology, Osaka University, Associate Professor, 工学部, 助教授 (30254452)
NAGATOMO Hideo Institute of Laser Engineering, Osaka University, Research Assistant, レーザー核融合研究センター, 助手 (10283813)
MURAKAMI Masakatsu Institute of Laser Engineering, Osaka University, Research Assistant, レーザー核融合研究センター, 助手 (80192772)
MUTSUOKA Chihiro Ehime University, Faculty of Science, Research Assistant, 理学部, 助手 (10270266)
ISHIZAKI Ryuichi National institute of Fusion Science, Osaka University, Research Assistant, ヘリカル研究部, 助手 (60301727)
長谷川 進 航空技術研究所, 数値宇宙, 研究官
|
Project Period (FY) |
1999 – 2001
|
Project Status |
Completed (Fiscal Year 2001)
|
Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2001: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2000: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1999: ¥1,800,000 (Direct Cost: ¥1,800,000)
|
Keywords | Rayleigh-Taylor instabi / Richtmyer-Meshkov instability / vortex sheet / ablation / nonlinear wave / molecular dynamic simulation / fractal / Lie group theory / 弱い非線形成長 / ダブルスパイラル / レーザー核融合 / 爆縮 / 流体不安定性 |
Research Abstract |
1. We have developed a weakly nonlinear theory of ablative Rayleigh-Taylor (RT) instability with a finite bandwidth Included self-consistently. The theory includes up to third order nonlinearity that results in saturation of linear growth and determines weakly nonlinear growth. It is found that the ablation effects reduce both the saturation amplitude of the linear growth and the weakly nonlinear growth. They are evaluated for plastic and DT targets. The weakly nonlinear growth is shown given by the product pf the linear growth and the saturation amplitude. 2. A third order nonlinear theory of Richtmyer-Meshkov (RM) instability has been developed by treating unstable interface as a vortex sheet with density jump. Nonlinear growth rates of spike and bubble are shown to agree well with hydrodynamic simulations. Circulation varies locally with time due to the density jump at the sheet and it introduces stretching and shrinking of the interface locally. 3. We have developed a molecular dynamic simulation program to treat RM instability in a cylindrical geometry, that conventional hydrodynamic codes fails to simulate. With the use of the code, we have investigated the stability of converging shocks and the nonlinear growth of RM instability, We have shown the increase of the nonlinear growth due to multiple shocks rebounded at the center and its dependence on mode number. 4. We have developed self-similar solutions of laser implosion in which thermal conduction plays an important rote by using Lie group theory. This model has been applied for hydrodynamically equivalent implosions in order to design future experimental facility for ignition and high gain in inertial fusion energy research.
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