This chapter reviews the progress accomplished since the redaction of the first ITER Physics Basis (1999 Nucl. Fusion39 2137–664) in the field of energetic ion physics and its possible impact on burning plasma regimes. New schemes to create energetic ions simulating the fusion-produced alphas are introduced, accessing experimental conditions of direct relevance for burning plasmas, in terms of the Alfvénic Mach number and of the normalised pressure gradient of the energetic ions, though orbit characteristics and size cannot always match those of ITER. Based on the experimental and theoretical knowledge of the effects of the toroidal magnetic field ripple on direct fast ion losses, ferritic inserts in ITER are expected to provide a significant reduction of ripple alpha losses in reversed shear configurations. The nonlinear fast ion interaction with kink and tearing modes is qualitatively understood, but quantitative predictions are missing, particularly for the stabilisation of sawteeth by fast particles that can trigger neoclassical tearing modes. A large database on the linear stability properties of the modes interacting with energetic ions, such as the Alfvén eigenmode has been constructed. Comparisons between theoretical predictions and experimental measurements of mode structures and drive/damping rates approach a satisfactory degree of consistency, though systematic measurements and theory comparisons of damping and drive of intermediate and high mode numbers, the most relevant for ITER, still need to be performed. The nonlinear behaviour of Alfvén eigenmodes close to marginal stability is well characterized theoretically and experimentally, which gives the opportunity to extract some information on the particle phase space distribution from the measured instability spectral features. Much less data exists for strongly unstable scenarios, characterised by nonlinear dynamical processes leading to energetic ion redistribution and losses, and identified in nonlinear numerical simulations of Alfvén eigenmodes and energetic particle modes. Comparisons with theoretical and numerical analyses are needed to assess the potential implications of these regimes on burning plasma scenarios, including in the presence of a large number of modes simultaneously driven unstable by the fast ions.
本章回顾了自第一版ITER物理基础（1999 Nucl. Fusion 39 2137–664）编写以来，高能离子物理领域所取得的进展及其对燃烧等离子体状态的潜在影响。介绍了模拟聚变产生的高能离子的新方法，这些方法能够在阿尔芬尼克·马赫数和高能离子归一化压力梯度方面达到与燃烧等离子体直接相关的实验条件，尽管轨道特征和尺寸并不总能与ITER完全匹配。基于对环向磁场波纹导致直接高能离子损失的实验和理论认识，预计ITER中的铁磁插入件将显著降低反剪切位形中的波纹引起的阿尔芬粒子损失。高能离子与扭曲模和撕裂模的非线性相互作用已在定性层面得到理解，但定量预测仍有所欠缺，特别是关于高能粒子对锯齿模的稳定化作用，而锯齿模又可能触发新经典撕裂模。目前已建立了大量关于与高能离子相互作用的模（如阿尔芬本征模）的线性稳定性数据库。理论预测与实验测量的模结构和驱动/阻尼率之间已取得较好的一致性，但仍需对中等和高环向模数（对ITER最为关键）的阻尼和驱动进行系统测量与理论对比。接近边际稳定性的阿尔芬本征模的非线性行为已在实验和理论上得到充分表征，这为从实测不稳定性谱特征中提取粒子相空间分布信息提供了机会。然而，对于强不稳定情形，即涉及导致高能离子再分布和损失的非线性动力学过程，现有数据仍然不足，相关研究主要依赖于非线性数值模拟。为评估这些过程对燃烧等离子体状态的潜在影响，仍需将数值模拟与理论分析相结合，特别是在多个模同时被高能离子驱动不稳定的情况下。