Multi-scale interactions between turbulence and magnetohydrodynamic instability driven by energetic particles
| Autor: | Akihiro Ishizawa, Yuji Nakamura, Kenji Imadera, Yasuaki Kishimoto |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Physics
Nuclear and High Energy Physics Tokamak magneto-hydrodynamic Scale (ratio) Turbulence Mechanics gyrokinetic simulation energetic particles Condensed Matter Physics Magneto hydrodynamic Instability turbulent transport law.invention Physics::Plasma Physics law Magnetohydrodynamic drive tokamak |
| Zdroj: | Nuclear Fusion. 61:114002 |
| ISSN: | 1741-4326 0029-5515 |
| Popis: | In order to realize high performance burning plasmas in magnetic-confinement fusion devices, such as tokamaks, both bulk plasma transport and that of energetic fusion alpha-particles, which result from different scale fluctuations with different free energy sources, have to be reduced simultaneously. Utilizing the advantage of global toroidal non-linear simulations covering a whole torus, here, we found a new coupling mechanism between the low-frequency micro-scale electromagnetic drift-wave fluctuations regulating the former, while the high-frequency macro-scale toroidal Alfven eigenmode (TAE) regulates the latter. This results from the dual spread of micro-scale turbulence due to the macro-scale TAE not only in wavenumber space representing local eddy size but also in configuration space with global profile variations. Consequently, a new class of turbulent state is found to be established, where the turbulence is homogenized on the poloidal cross-section with exhibiting large-scale structure, which increases fluctuation levels and then both transports, leading to deterioration in the fusion performance. |
| Databáze: | OpenAIRE |
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