2006 Fiscal Year Final Research Report Summary
Numerical Studies of Structure Formation of Plasmas in Non-equilibrium Open System through Modeling of Inter-hierarchy Interaction
| Project/Area Number |
15540386
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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 |
原子・分子・量子エレクトロニクス・プラズマ
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| Research Institution | National Institute for Fusion Science |
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Principal Investigator |
MIURA Hideaki National Institute for Fusion Science, Theory and Computer Simulation Center, Associate Professor, 理論・シミュレーション研究センター, 助教授 (40280599)
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| Co-Investigator(Kenkyū-buntansha) |
MIZUGUCHI Naoki National Institute for Fusion Science, Department of Large Helical Device Project, Research Associate, 大型ヘリカル研究部, 助手 (70332187)
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| Project Period (FY) |
2003 – 2006
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| Keywords | structural formation / numerical simulation / two-fluid model / pressure-driven instability / drift model / ELM / plasma flow / adaptive mesh refinement |
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| Research Abstract |
This study aims at developing a large-scale numerical simulation method by using a new modeling which can treat self-consistently a multi-scaled spatio-temporal domain, and applying it to the dynamics of structural transient phenomena in plasma. The results are as follows :
1. Analysis of self-organization process by means of two-fluid model
A two-fluid model based on nonlinear compressible Hall-MHD equations has been developed. In contrast to conventional MHD models, the formation of cross-field plasma flows which is a nature of double-Beltrami (DB) equilibria, and constraint of the process is confirmed.
2. Structure formation in tori with flows
Relaxation mechanisms in a high-beta tori with flows are studied. For the cases of numerical equilibria based on the modified Grad-Shafranov equation, the spontaneous formation of poloidal flows in a translation process of a field-reversed configuration, and a diamagnetic rotation, the pressure-driven instabilities are analyzed. Selective stabilization due to flows are clarified. The development of pressure-driven instabilities in the large helical device (LHD) plasma has shown the suppression effect due to the spontaneous toroidal flows and the compressibility.
3. Edge-localized mode (ELM) in spherical tokamak (ST)
Abovementioned models are applied to ELM in ST. The formation of filaments on ELMs are well reproduced. The soundness of the model is confirmed against the diamagnetic effect.
4. Formation of multi-layered structure by means of adaptive mesh refinement (AMR) method
A numerical code with a high-resolution compact difference method has been modified to include the AMR method. The effectiveness of the code towards the MHD simulations is confirmed.
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