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.
我们使用局部δf回旋动理学代码GS2，研究了磁面形状对两个高形变、低β和高β的JT-60SA相关平衡态的影响，并与GKV代码进行了成功比对。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，通过最小化拉长率可以减小湍流径向输运通量。我们将结果解释为局部磁剪切与有限拉莫尔半径（FLR）稳定化之间的竞争。电磁研究表明，由于相对于离子温度梯度不稳定性的FLR效应敏感性增强，增加形变可以稳定动理学气球模。然而，在足够高的β下，增加拉长率会削弱局部磁剪切稳定化，从而阻碍进入气球模第二稳定区的通道。