托卡马克等离子体中快粒子触发的高频鱼骨模不稳定性研究

本文考虑托卡马克等离子体中快粒子的空间密度分布剖面,在中性束及电子回旋共振加热的条件下,建立了研究鱼骨模的色散关系并对鱼骨模作了数值研究。结果表明:快粒子对内扭曲模有致稳作用,且在近轴加热条件下可激发高频鱼骨模,其频率与快粒子的环向进动频率一致。鱼骨模的增长率与快粒子的密度梯度有关,一般随密度梯度的增加而增大。在高比压区间,勉强通行快粒子可驱动鱼骨模进入第二稳定区,在该区域鱼骨模是稳定的。

Study on Unstability of High Frequency Fishbone Mode Triggered by Fast Particle in Tokamak Plasma

Based on neutral beam injection heating and electron cyclotron resonance heating,a general dispersion relation for fishbone-like internal kink mode was obtained when the spatial density profile of fast particle in Tokamak plasma was taken into account.The numerical results show that the internal kink mode can be stabilized by fast particles and high frequency fishbone mode can be triggered by fast particles in the case of near-axis heating.The real frequency of the mode is poroportional to the averaged toroidal precession frequency of fast particles.The growth rate of the mode depends on density gradient of fast particles and increases with density gradient.The fishbone mode can be driven into the second stable regime by barely passing fast particles and becomes stable in high specific pressure region.