The energetic-particle-induced geodesic acoustic mode (EGAM) is studied using gyrokinetic particle simulations in tokamak plasmas. In our simulations, exponentially growing EGAMs are excited by energetic particles with a slowing-down distribution. The frequencies of EGAMs are always below the frequencies of GAMs, which is due to the non-perturbative contribution of energetic particles (EPs). The mode structures of EGAMs are similar to the corresponding mode structures of GAMs. Our gyrokinetic simulations show that a high EP density can enhance the EGAM growth rate, due to high EP free energy, and that EPs' temperature and the pitch angle of the distribution modify the EGAM frequency/growth rate by means of the resonance condition. Kinetic effects of the thermal electrons barely change the EGAM frequency, and have a weak damping effect on the EGAM. Benchmarks between the gyrokinetic particle simulations and a local EGAM dispersion relation exhibit good agreement in terms of EGAM ...

中文翻译：

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动能粒子模拟中高能粒子诱导的测地线声模的验证

使用托卡马克等离子体中的回旋粒子模拟研究了高能粒子诱发的测地声模（EGAM）。在我们的模拟中，呈指数增长的EGAM被具有缓慢分布的高能粒子激发。EGAM的频率始终低于GAM的频率，这是由于高能粒子（EP）的无扰动作用所致。EGAM的模式结构类似于GAM的相应模式结构。我们的运动学仿真表明，由于高的EP自由能，高的EP密度可以提高EGAM的生长速率，并且EP的温度和分布的俯仰角会通过共振条件改变EGAM频率/增长率。热电子的动力学效应几乎不会改变EGAM频率，并且对EGAM的阻尼作用较弱。陀螺动力学粒子模拟与局部EGAM色散关系之间的基准在EGAM方面表现出良好的一致性...