Multi-scale interactions between turbulence and magnetohydrodynamic instability driven by energetic particles

Nuclear Fushion

article

A. Ishizawa¹  K. Imadera¹  Y. Nakamura¹  Y. Kishimoto¹ 

[1] Graduate School of Energy Science, Kyoto University

关键词: turbulent transport;    magneto-hydrodynamic;    gyrokinetic simulation;    energeticparticles;    tokamak;   

DOI  :  10.1088/1741-4326/ac1f61

来源: Institute of Physics Publishing Ltd.

【 摘 要 】

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.

【 授权许可】

Unknown