Compressional Alfvén eigenmodes excited by runaway electrons

Abstract Compressional Alfvén eigenmodes (CAEs) driven by energetic ions have been observed in magnetic fusion experiments. In this paper, we show that the modes can also be runaway electrons formed post-disruption plasma, which may explain kinetic instabilities DIII-D disruption experiments with massive gas injection. The spatial structure is calculated, as are frequencies agreement experimental observations. Using a electron distribution function obtained from simulation, mode growth rates calculated and found to exceed collisional damping rate when density exceeds threshold value. excitation of CAEs poses new possible approach mitigate seed during current quench surpassing avalanche.