电流猝灭过程中逃逸电子电流平台形成的混合动理学-MHD模拟
Hybrid kinetic-MHD simulation on the formation of runaway electron current plateau during a current quench process
中文总结 AI 辅助
本文开发耦合NIMROD代码三维非线性扩展MHD模型的全粒子PIC模型，模拟电流猝灭中逃逸电子电流平台形成，揭示高度相对论性逃逸电子的梯度-B与曲率漂移对其产生和运动的显著作用。
中文摘要 AI 辅助
逃逸电子（RE）的产生对大电流托卡马克装置的运行至关重要。本文开发了一种用于RE动力学的全粒子（full-f）粒子-in-cell（PIC）模型，并将其与NIMROD代码中实现的三维非线性扩展磁流体动力学（MHD）模型耦合。该模型采用解析源项描述RE的产生，并引导RE沿导向中心（GC）轨道运动。我们利用该模型模拟了等离子体破裂过程中RE电流平台的形成，此时等离子体电流由RE电流主导。当忽略RE的GC漂移时，该模型与多个基于流体模型的RE代码的结果吻合良好。对于高度相对论性的RE，在电流猝灭过程中安全因子分布增大的情况下，梯度-B漂移和曲率漂移会对RE的产生和运动产生显著影响。
英文摘要
Runaway electron (RE) generation is of great concern for high-current tokamak operations. A full-f particle-in-cell (PIC) model for RE dynamics has been developed and coupled with the 3D nonlinear extended magnetohydrodynamic (MHD) model implemented in the NIMROD code. Our model accounts for RE generation using analytical source terms and advances the RE motion along guiding-center (GC) orbits. The model was employed to simulate the formation of RE current plateau during a disruption, in which the plasma current becomes dominated by the RE current. The model agrees well with several RE codes based on fluid models when the RE GC drifts are ignored. For highly relativistic REs, the grad-$B$ and curvature drifts can play a significant role in the RE generation and motion due to the increase in the safety factor profile during the current quench process.
