论文标题
与各向同性减速快速粒子分布的AlfVén模式活动的旋转模型
Gyrokinetic modelling of the Alfvén mode activity in ASDEX Upgrade with an isotropic slowing-down fast-particle distribution
论文作者
论文摘要
在本文中，通过分析具有全局，电磁，旋转电磁粒子中的gyrokinetic粒子中的仿真结果，在现实的ASDEX升级平衡中研究了AlfVén模式的演变。通过新实施的各向同性减速和麦克斯韦分布函数对能量粒子进行建模。数值结果的比较表明，用等效的麦克斯韦（Maxwellian）而不是用减速模型对能量颗粒进行建模不会影响驱动的AlfVén模式的频率，而其生长速率似乎被低估的定量差异低至30％。另外，各向同性放慢速度的选择可以更好地描述主要的AlfVén模式频率的非线性修饰，而等效的Maxwellian则低估了它。与实验光谱图进行了良好的比较。
In the present paper, the evolution of the Alfvén modes is studied in a realistic ASDEX Upgrade equilibrium by analysing the results of simulations with the global, electromagnetic, gyrokinetic particle-in-cell code ORB5. The energetic particles are modelled both via the newly implemented isotropic slowing-down and with Maxwellian distribution functions. The comparison of the numerical results shows that modelling the energetic particles with the equivalent Maxwellian rather than with the slowing-down, does not affect the frequency of the driven Alfvén mode, while its growth rate appears to be underestimated with a quantitative difference as large as almost 30 %. Additionally the choice of the isotropic slowing-down allows a better description of the nonlinear modification of the dominant Alfvén mode frequency, while an equivalent Maxwellian underestimates it. A good comparison with the experimental spectrogram is found.
