2006 Fiscal Year Final Research Report Summary
Theoretical and simulation study of the instabilities in the frequency range of Alfven eigenmodes
Project/Area Number |
16560728
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Nuclear fusion studies
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Research Institution | National Institute for Fusion Science |
Principal Investigator |
TODO Yasushi 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 (00249971)
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Project Period (FY) |
2004 – 2006
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Keywords | energetic particle / Alfven eigenmode / energetic particle mode / MHD / total characteristic method / fusion plasma / simulation |
Research Abstract |
We investigated the Alfven eigenmodes and energetic-particle modes using the energetic-particles and MHD hybrid simulation code, MEGA. The following are the research products of the present Grand-in-Aid for Scientific Research. 1. The detailed simulation study of the properties of nonlocal energetic-particle mode in the JT-60U plasmas revealed that the radial width of the mode strongly depends on both the energetic-particle orbit width and the energetic-particle pressure. 2. With regards to the energetic-particle continuum modes, it was clearly demonstrated with computer simulations that the mode frequency is in agreement with the energetic-particle orbit frequency. 3. It was found in the nonlinear simulations that the saturation amplitude of Alfven eigenmodes is suppressed by the MHD nonlinear effect. 4. The MEGA code was extended for the simulations of helical plasmas. Simulations of the Alfven eigenmodes in the LHD plasmas were carried out. 5. The MEGA code has been extended to include the ion finite Larmor radius effects and the electron Landau damping. A new simulation, method "total characteristic method" that guarantees the conservation properties in the low noise particle-in-cell simulation was devised. A gyrokinetic simulation model for electromagnetic phenomena was constructed using the total characteristic method. It was demonstrated that the real frequency and the damping rate of kinetic Alfven waves are accurately computed with the new simulation model. We can create 3-dimensional gyrokinetic electromagnetic plasma simulation codes for torus plasmas using the total characteristic method.
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