The fishbone-induced transport of alpha particles is computed for the ITER 15 MA baseline scenario, using the nonlinear hybrid Kinetic-MHD code XTOR-K. Two limit cases have been studied, in order to analyse the characteristic regimes of the fishbone instability : the weak kinetic drive limit and the strong kinetic drive limit. In both those regimes, characteristic features of the n = m = 1 fishbone instability are recovered, such as a strong up/down-chirping of the mode frequency, associated with a resonant transport of trapped and passing alpha particles. The effects of the n = m = 0 sheared poloidal and toroidal plasma rotation are taken into account in the simulations. The shear is not negligible, which implies that the fishbone mode frequency has a radial dependency, impacting the wave-particle resonance condition. Phase space hole and clump structures are observed in both nonlinear regimes, centered around the precessional and passing resonances. These structures remains attached to the resonances as the different mode frequencies chirp up and down. In the nonlinear phase, the transport of individual resonant trapped particles is identified to be linked to mode-particle synchronization. On this basis, a partial mechanism for the nonlinear coupling between particle transport and mode dominant down-chirping is proposed. The overall transport of alpha particles inside out the q = 1 surface is of order 2-5% of the initial population between the simulations. The loss of alpha power is found to be directly equal to the loss of alpha particles.

中文翻译：

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ITER上鱼骨诱导的α传输的非线性动力学

使用非线性混合动力学-MHD 代码 XTOR-K，针对 ITER 15 MA 基线情景计算了鱼骨诱导的 α 粒子传输。为了分析鱼骨不稳定性的特征状态，研究了两种极限情况：弱动力驱动极限和强动力驱动极限。在这两种情况下，n = m = 1 鱼骨不稳定性的特征被恢复，例如模式频率的强烈向上/向下啁啾，与捕获和通过的 alpha 粒子的共振传输相关。在模拟中考虑了 n = m = 0 剪切极向和环形等离子体旋转的影响。剪切是不可忽略的，这意味着鱼骨模式频率具有径向依赖性，影响波粒共振条件。在两个非线性区域中都观察到相空间孔和团块结构，以岁差和传递共振为中心。随着不同模式频率上下啁啾，这些结构仍然与共振相连。在非线性阶段，单个共振捕获粒子的传输被确定为与模式粒子同步有关。在此基础上，提出了粒子传输与模式主导下啁啾非线性耦合的部分机制。q = 1 表面内外的 alpha 粒子的整体传输约为模拟之间初始种群的 2-5%。发现阿尔法功率的损失直接等于阿尔法粒子的损失。随着不同模式频率上下啁啾，这些结构仍然与共振相连。在非线性阶段，单个共振捕获粒子的传输被确定为与模式粒子同步有关。在此基础上，提出了粒子传输与模式主导下啁啾非线性耦合的部分机制。q = 1 表面内外的 alpha 粒子的整体传输约为模拟之间初始种群的 2-5%。发现阿尔法功率的损失直接等于阿尔法粒子的损失。随着不同模式频率上下啁啾，这些结构仍然与共振相连。在非线性阶段，单个共振捕获粒子的传输被确定为与模式粒子同步有关。在此基础上，提出了粒子传输与模式主导下啁啾非线性耦合的部分机制。q = 1 表面内外的 alpha 粒子的整体传输约为模拟之间初始种群的 2-5%。发现阿尔法功率的损失直接等于阿尔法粒子的损失。提出了粒子传输和模式主导下啁啾之间非线性耦合的部分机制。q = 1 表面内外的 alpha 粒子的整体传输约为模拟之间初始种群的 2-5%。发现阿尔法功率的损失直接等于阿尔法粒子的损失。提出了粒子传输和模式主导下啁啾之间非线性耦合的部分机制。q = 1 表面内外的 alpha 粒子的整体传输约为模拟之间初始种群的 2-5%。发现阿尔法功率的损失直接等于阿尔法粒子的损失。