论文标题
$ 1/1 $ energetic-Ion驱动的电阻互换模式的饱和阶段的理论分析
Theoretical analysis of the saturation phase of the $1/1$ energetic-ion-driven resistive interchange mode
论文作者
论文摘要
本研究的目的是分析LHD等离子体中能量离子驱动的电阻互换模式(EIC)的饱和度状态。一组非线性模拟由FAR3D代码执行,该代码使用降低的MHD模型为热等离子体以及用于高能颗粒(EP)物种的陀螺素模型的模型。通过修改平均漂移速度操作员的修改,将其陷入困境的EP组件包括在内。非线性模拟结果表明,相对于实验观察结果,相似的1/1 EIC饱和阶段相对于EP $β$的增强,从而增强了N/M = 1/1的电阻互换模式(RIC)的幅度和宽度,而EP $β$的增加,对1/1 EIC激发的EP Beta阈值的增加,并增加了1/1 EIC的EIC eic eic eic eic eic eic的启发率。触发事件的触发。在突发事件中计算的1/1 EIC的频率为9.4 kHz,2/2和3/3泛音不稳定,与实验中测得的频率范围和复杂模式结构一致。此外,由于3/4和2/3 EPM的非线性不稳定,模拟显示了1/1 EIC的内向传播,从而导致爆发事件期间共振之间的部分重叠。最后,对1/1 EIC稳定阶段的分析表明,一旦由1/1 EIC诱导的压力曲线中的扁平化消失,导致在血浆周围的压力梯度的检索和克服RIC稳定性限制。
The aim of the present study is to analyze the saturation regime of the energetic-ion-driven resistive interchange mode (EIC) in the LHD plasma. A set of non linear simulations are performed by the FAR3d code that uses a reduced MHD model for the thermal plasma coupled with a gyrofluid model for the energetic particles (EP) species. The hellically trapped EP component is introduced through a modification of the averaged drift velocity operator to include their precessional drift. The non linear simulation results show similar 1/1 EIC saturation phases with respect to the experimental observations, reproducing the enhancement of the n/m = 1/1 resistive interchange modes (RIC) amplitude and width as the EP $β$ increases, the EP beta threshold for the 1/1 EIC excitation, the further destabilization of the 1/1 EIC as the population of the helically trapped EP increases and the triggering of burst events. The frequency of the 1/1 EIC calculated during the burst event is 9.4 kHz and the 2/2 and 3/3 overtones are destabilized, consistent with the frequency range and the complex mode structure measured in the experiment. In addition, the simulation shows the inward propagation of the 1/1 EIC due to the non linear destabilization of the 3/4 and 2/3 EPMs, leading to the partial overlapping between resonances during the burst event. Finally, the analysis of the 1/1 EIC stabilization phase shows the excitation of the 1/1 RIC as soon as the flattening induced by the 1/1 EIC in the pressure profile vanishes, leading to the retrieval of the pressure gradient at the plasma periphery and the overcoming of the RIC stability limit.