We have used the local-δf gyrokinetic code GS2 to perform studies of the effect of flux-surface shaping on two highly-shaped, low- and high-β JT-60SA-relevant equilibria, including a successful benchmark with the GKV code. We find that for a high-performance plasma, i.e. one with high plasma beta and steep pressure gradients, the turbulent outwards radial fluxes may be reduced by minimizing the elongation. We explain the results as a competition between the local magnetic shear and finite-Larmor-radius (FLR) stabilization. Electromagnetic studies indicate that kinetic ballooning modes are stabilized by increased shaping due to an increased sensitivity to FLR effects, relative to the ion-temperature-gradient instability. Nevertheless, at high enough β, increased elongation degrades the local magnetic shear stabilization that enables access to the region of ballooning second-stability.

我们已经使用局部δf陀螺动力学代码GS2来研究通量表面成形对两个高度成形、低和高β JT-60SA 相关平衡的影响，包括与GKV的成功基准代码。我们发现，对于高性能等离子体，即具有高等离子体 β 和陡峭压力梯度的等离子体，可以通过最小化伸长率来减少向外的湍流径向通量。我们将结果解释为局部磁剪切和有限拉莫尔半径 (FLR) 稳定性之间的竞争。电磁研究表明，相对于离子温度梯度不稳定性，由于对 FLR 效应的敏感性增加，因此通过增加形状来稳定动力学气球模式。然而，在足够高的β 下，增加的伸长率会降低局部磁剪切稳定性，从而能够进入膨胀第二稳定性区域。