Runaway currents have been detected during unintended disruptions in the circular plasma with the limiter configuration in the Experimental Advanced Superconducting Tokamak (EAST). The runaway electron (RE) plateau can carry up to 80% of the pre-disruption plasma current. The highest runaway currents correspond to the lowest loop voltage, which is contrary to the observations made in most tokamaks. This anomalous behavior is attributed to the acceleration of the pre-existing wave resonant suprathermal electrons by lower hybrid waves during the disruption decay phase. Two distinct types of RE-related relaxation phenomena, distinguished on the basis of the amplitude of the magnetic fluctuations, have been found during the disruptions. Large-amplitude magnetohydrodynamic activity with indications of RE loss is observed during the RE plateau when the edge safety factor decreases to less than 3, and the external kink mode is discussed to resolve this anomaly. Burst-like relaxations with small-amplitude magnetic fluctuations and ∼0.6 kHz frequency are confirmed from the spikes in the hard x-ray array signals under a negative loop voltage. Measurement of the RE energy distribution suggests that the instability is driven by medium-energy REs.

在实验性先进超导托卡马克 (EAST) 中使用限制器配置在圆形等离子体意外中断期间检测到失控电流。失控电子 (RE) 平台可以承载高达 80% 的中断前等离子体电流。最高的失控电流对应于最低的回路电压，这与大多数托卡马克的观察结果相反。这种异常行为归因于在破坏衰减阶段较低的混合波对预先存在的波共振超热电子的加速。在破坏过程中发现了两种不同类型的稀土相关弛豫现象，根据磁波动的幅度进行区分。当边缘安全系数降低到小于 3 时，在 RE 高原期间观察到具有 RE 损失迹象的大振幅磁流体动力学活动，并且讨论了外部扭结模式来解决这种异常。在负环路电压下，硬 X 射线阵列信号中的尖峰证实了具有小幅度磁波动和 ~0.6 kHz 频率的突发​​式弛豫。RE 能量分布的测量表明不稳定性是由中等能量 RE 驱动的。