2006 Fiscal Year Final Research Report Summary
Study of MHD characteristic of burning plasmas by the kinetic MHD model
| Project/Area Number |
15560716
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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 |
Nuclear fusion studies
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| Research Institution | Yamaguchi University |
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Principal Investigator |
NAITOU Hiroshi Yamaguchi University, Graduate School of Science and Engineering, Professor, 大学院理工学研究科, 教授 (10126881)
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| Co-Investigator(Kenkyū-buntansha) |
FUKUMASA Osamu Yamaguchi University, Graduate School of Science and Engineering, Professor, 大学院理工学研究科, 教授 (20026321)
YAGI Masatoshi Kyushu University, Research Institute for Applied Mechanics, Professor, 応用力学研究所, 教授 (70274537)
TOKUDA Shinji Japan Atomic Energy Agency, Fusion Research and Development Directorate, Principal Scientist, 核融合研究開発部門, 研究主幹 (60354578)
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| Project Period (FY) |
2003 – 2006
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| Keywords | nuclear fusion / extended MHD model / kinetic model / internal kink mode / vortex / Kelvin-Helmholtz instability / international information exchange |
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| Research Abstract |
As the MHD phenomena in tokamaks enter into the collisionless regime, needs for the kinetic (or extended) MHD simulation have been increased. We have developed the simulation model which includes electron inertia, diamagnetic effect, and ion Landau damping. To simulate the m=1 and n=1 internal kink mode, the collisionless skin depth (d_e〜1mm) which is three orders of magnitude smaller than the minor radius is resolved. The results are summarized as follows : (1) As the pressure gradient increases the internal kink mode (IK mode) is stabilized by the diamagnetic effects but the new mode appears with the smaller growth rate and with the frequency of drift wave (DIK mode). There is a stability window between unstable regions of both modes if the ion Landau damping is included. (2) DIK mode can also cause full magnetic reconnection. The linear mode pattern of the DIK mode is basically similar to that of the IK mode but has a strong poloidal shear flow to generate small vortices in the nonlinear stage due to the Kelvin-Helmholtz like instability. There appears turbulent region due to the nonlinear coupling of vortices. The DIK mode is first stabilized by the excitation of vortices but later it is destabilized with enhanced growth rate.
We have also executed the multi-scale simulation of tearing mode and drift-wave turbulence and found that the growth rate of tearing mode is accelerated by the nonlinear coupling.
The ideal linear MHD analysis code MARG2D is improved to simulate the free-boundary peeling-ballooning mode appearing in the tokamak peripheral region.
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