Energetic-particle-driven geodesic acoustic modes (EGAMs) channeling in the Large Helical Device (LHD) plasmas are systematically investigated for the first time using MEGA code. MEGA is a hybrid simulation code for energetic particles interacting with a magnetohydrodynamic (MHD) fluid. In the present work, both the energetic particles and the bulk ions are described kinetically. The EGAM profiles in the three-dimensional form is illustrated. Then, EGAM channeling behaviors are analyzed under different conditions. During the EGAM activities without frequency chirping, EGAM channeling occurs in the linear growth stage but terminates in the decay stage after the saturation. During the EGAM activities with frequency chirping, EGAM channeling occurs continuously. Also, low-frequency EGAM makes the energy transfer efficiency (Eion/EEP) higher, and this is confirmed by changing the energetic particle pressure, energetic particle beam velocity, and energetic particle pitch angle. Moreover, higher bulk ion temperature makes the energy transfer efficiency higher. In addition, under a certain condition, the energy transfer efficiency in the deuterium plasma is lower than that in the hydrogen plasma.

中文翻译：

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使用 MEGA 代码系统研究高能粒子驱动的测地线声模通道

首次使用 MEGA 代码系统地研究了大螺旋装置 (LHD) 等离子体中的高能粒子驱动测地线声学模式 (EGAM) 通道。MEGA 是一种用于与磁流体动力学 (MHD) 流体相互作用的高能粒子的混合模拟代码。在目前的工作中，高能粒子和体离子都被动力学描述。显示了三维形式的 EGAM 配置文件。然后，分析了不同条件下的 EGAM 通道行为。在没有频率啁啾的 EGAM 活动期间，EGAM 通道发生在线性增长阶段，但在饱和后的衰减阶段终止。在带有频率啁啾的 EGAM 活动期间，EGAM 信道连续发生。此外，低频 EGAM 使能量传输效率 (Eion/EEP) 更高，这是通过改变高能粒子压力、高能粒子束速度和高能粒子俯仰角来证实的。此外，较高的体离子温度使能量转移效率更高。此外，在一定条件下，氘等离子体的能量传递效率低于氢等离子体。