Verification of Energetic-Particle-Induced Geodesic Acoustic Mode in Gyrokinetic Particle Simulations
Verification of Energetic-Particle-Induced Geodesic Acoustic Mode in Gyrokinetic Particle Simulations
复制标题
回旋粒子模拟中高能粒子诱发的测地声学模式的验证
DOI：
10.1088/0256-307x/37/9/095201
复制
发表时间：
2020
影响因子：
3.5
通讯作者：
Li Ding
中科院分区：
文献类型：
--
作者：
Chen Yang;Zhang Wenlu;Bao Jian;Lin Zhihong;Dong Chao;Cao Jintao;Li Ding
利用回旋粒子模拟方法研究了托卡马克等离子体中能量粒子诱导的测地声学模（EGAM）。在我们的模拟中，指数增长的EGAM由具有减速分布的高能粒子激发。由于高能粒子的非微扰贡献，EGAM的频率总是低于GAM的频率。EGAM的模式结构类似于GAM的相应模式结构。我们的gyrokinetic模拟表明，高EP密度可以提高EGAM的生长速率，由于高EP自由能，和EP的温度和分布的俯仰角修改EGAM频率/生长速率的共振条件的装置。热电子的动力学效应几乎不改变EGAM的频率，并且对EGAM有微弱的阻尼作用。gyrokinetic粒子模拟和本地EGAM色散关系之间的基准表现出良好的协议EGAM频率和增长率。
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 frequency and growth rate.