局部电流驱动对稳态撕裂模不稳定性的影响

Effect of Localized Current Drive on Nonlinear Tearing Mode

采用二维可压缩磁流体模型,在平板位型下研究了外部局域电流驱动对稳态撕裂模的影响,详细研究了驱动电流的大小和其开始沉积时间对撕裂模不稳定性的影响。研究结果显示:外部驱动电流越大其对磁岛的抑制作用越大,但最后磁岛的饱和宽度也越宽,主要是因为当外部驱动电流沉积在磁岛X点时会使X点位置偏移,导致稳态撕裂模失稳;而且局部驱动电流对撕裂模的抑制作用跟撕裂模所处的状态也有关,外部驱动电流在磁岛增长率小于零的区间开始沉积对撕裂模抑制效果最佳。

A two-dimensional compressible magnetohydrodynamics model in slab geometry is adopted to study the effect of external localized current drive on the tearing mode. Magnetic island can be significantly suppressed by the external localized current drive with appropriate conditions. If the amplitude of driven current density is larger,the magnetic island can be more effectively suppressed,but the saturated width of magnetic island would be wider. The suppression effect also relates to the condition of background plasma and the optimal initial depositional time of external driven current is at the time interval where the growth rate of the magnetic is negative.