Observation of an Energetic-Particle-Driven Instability in the Wall-Stabilized High-β Plasmas in the JT-60U Tokamak
Observation of an Energetic-Particle-Driven Instability in the Wall-Stabilized High-β Plasmas in the JT-60U Tokamak
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DOI：
10.1103/physrevlett.103.045001
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发表时间：
2009-07-24
影响因子：
8.6
通讯作者：
Ozeki, T.
中科院分区：
文献类型：
--
作者：
Matsunaga, G.;Aiba, N.;Ozeki, T.
我们已经观察到，在没有导电壁的情况下，在理想β极限以上的高β等离子体中存在爆发模式。模态频率随模态幅值的增大而减小，其初始值接近于垂直中性光束捕获的高能粒子的进动频率。模态结构沿q = 2表面呈径向延伸，并在其周围有一个峰。这种模式最终可以触发电阻壁模式（RWM），尽管有足够的等离子体旋转来稳定RWM。结果表明，该模式是由捕获的高能粒子驱动的。该模式归因于捕获的高能粒子之间的相互作用和在壁稳定的高β (N)区域的边缘稳定模式。
We have observed a bursting mode in the high-beta plasmas above the ideal beta limit without a conducting wall. The mode frequency is chirping down as the mode amplitude increases, and its initial value is close to the precession frequency of the trapped energetic particle from the perpendicular neutral beams. The mode structure is radially extended with a peak around the q = 2 surface. This mode can finally trigger the resistive wall mode (RWM) despite enough plasma rotation for RWM stabilization. It is concluded that the mode is driven by trapped energetic particles. The mode is attributed to the interaction between the trapped energetic particles and a marginally stable mode in the wall-stabilized high-beta(N) region.