We set up a mapping procedure able to translate the evolution of the radial profile of fast ions, interacting with toroidal Alfvén Eigenmodes, into the dynamics of an equivalent one-dimensional bump-on-tail system. We apply this mapping technique to reproduce the relevant ITER simulations, which clearly outline deviations from the diffusive quasi-linear (QL) model. Our analysis demonstrates the capability of the one-dimensional beam-plasma dynamics to predict the relevant features of the non-linear hybrid LIGKA/HAGIS simulations. In particular, we clearly identify how the deviation from the QL evolutive profiles is due to the presence of avalanche processes. A detailed analysis regarding the reduced dimensionality is also addressed, by means of phase-space slicing based on constants of motion. In the conclusions, we outline the main criticalities and outcomes of the procedure, which must be satisfactorily addressed to make quantitative predictions on the observed outgoing fluxes in a Tokamak device.
我们建立了一种映射方法，能够将快速离子与环形阿尔芬本征模相互作用时的径向剖面演化，转化为等效的一维“凸起-尾部”系统的动力学行为。我们应用这一映射技术来重现相关的ITER模拟结果，这些模拟清晰地揭示了与扩散性准线性模型之间的偏差。我们的分析证明了，一维束-等离子体动力学能够预测非线性混合LIGKA/HAGIS模拟的关键特征。特别是，我们明确识别出，与准线性演化剖面的偏差源于雪崩过程的存在。此外，我们还通过基于运动常量的相空间切片方法，对降维问题进行了详细分析。在结论部分，我们概述了该方法的主要难点与成果，这些必须得到妥善解决，才能对托卡马克装置中的外流输运做出定量预测。