We explore the impact of realistic plasma resistivity on the linear stability of peeling-ballooning (PB) modes in tokamak discharges with low-aspect ratio. For this study we consider discharges that are subject to edge-localized modes (ELMs) in the National Spherical Torus Experiment (NSTX). Employing the state of the art extended-magnetohydrodynamic (MHD) code M3D-C1 it is demonstrated that non-ideal effects can significantly affect PB stability thresholds in NSTX discharges. In particular, robust resistive PB modes are found to exist well before the ideal PB stability threshold is met. These novel results can explain why ideal-MHD theory often does not accurately describe ELM onset in spherical torus configurations, and also present a valuable basis for the development of a predictive model for ELMs in low-aspect ratio tokamaks.

我们探讨了实际等离子体电阻率对低纵横比托卡马克放电中剥离-气球 (PB) 模式线性稳定性的影响。在这项研究中，我们考虑了在国家球形环面实验 (NSTX) 中受边缘局部模式 (ELM) 影响的放电。采用最先进的扩展磁流体动力学 (MHD) 代码 M3D-C1 证明，非理想效应会显着影响 NSTX 放电中的 PB 稳定性阈值。特别是，在满足理想的 PB 稳定性阈值之前，发现稳健的电阻 PB 模式已经存在。这些新颖的结果可以解释为什么理想 MHD 理论通常不能准确描述球形环面配置中的 ELM 起始，并且也为开发低纵横比托卡马克中 ELM 的预测模型提供了宝贵的基础。