The axisymmetric (n = 0) resistive wall mode instability is numerically investigated for the negative triangularity plasma shape, which has shown several benefits in terms of improved confinement time and fusion engineering. To evaluate the shape effects, we modified a MHD instability code AVSTAB (Axisymmetric Vertical STABility), which calculates the marginally controllable elongation in a simplified feedback capability parameter. The plasma characteristics (poloidal beta and internal inductance) as well as the geometric effects (wall shape and plasma location) are important to determine the instability. In contrast to positive triangularity, the higher poloidal beta provides more instability drive for the negative triangularity because of the higher Shafranov shift and the higher elongation of the inner flux surface of the MHD equilibrium. Non-conformal wall shapes to the plasmas (positive triangularity wall and negative triangularity plasma) are found to be rather helpful to stabilize the n = 0 mode, unless the plasma is too close to the walls at the nulls for the opposite triangularity.

轴对称 ( n= 0) 对负三角形等离子体形状的电阻壁模式不稳定性进行了数值研究，这在改进限制时间和聚变工程方面显示了一些好处。为了评估形状效应，我们修改了 MHD 不稳定性代码 AVSTAB（轴对称垂直稳定性），它以简化的反馈能力参数计算边缘可控的伸长率。等离子体特性（极向贝塔和内部电感）以及几何效应（壁形状和等离子体位置）对于确定不稳定性很重要。与正三角形相反，由于更高的 Shafranov 位移和 MHD 平衡的内部通量表面的更高伸长率，更高的极向贝塔为负三角形提供了更多的不稳定性驱动。n = 0 模式，除非等离子体太靠近相反三角形的零点处的壁。