Low-$n$ global ideal MHD instabilities in CFETR baseline scenario

• Main Authors: Han, Rui, Zhu, Ping, Banerjee, Debabrata, Cheng, Shikui, Yan, Xingting, Zheng, Linjin
• Format: Journal Article
• Language: English
• Published: 23.11.2019
• Subjects: Physics - Plasma Physics
• DOI: 10.48550/arxiv.1911.11615

This article reports an evaluation on the linear ideal magnetohydrodynamic (MHD) stability of the China Fusion Engineering Test Reactor (CFETR) baseline scenario for various first-wall locations. The initial-value code NIMROD and eigen-value code AEGIS are employed in this analysis. A good agreement is achieved between two codes in the growth rates of $n=1-10$ ideal MHD modes for various locations of the perfect conducting first-wall. The higher-$n$ modes are dominated by ballooning modes and localized in the pedestal region, while the lower-$n$ modes have more prominent external kink components and broader mode profiles. The influences of plasma-vacuum profile and wall shape are also examined using NIMROD. In presence of resistive wall, the low-$n$ ideal MHD instabilities are further studied using AEGIS. For the designed first-wall location, the $n = 1$ resistive wall mode (RWM) is found unstable, which could be fully stabilized by uniform toroidal rotation above 2.9\% core Alfv\'en speed.