Super-thermal ions and electrons occur in both space and fusion plasmas. Because these energetic particles (EP) have large velocities, EP orbits necessarily deviate substantially from magnetic surfaces. Orbits are described by conserved constants of motion that define topological boundaries for different orbit types. Electric and magnetic field perturbations produced by instabilities can disrupt particle orbits, causing the constants of motion to change. The statistics of the “kicks” associated with these perturbations determines the resulting cross field transport. A unifying theme of this tutorial is the importance of the perturbation’s phase at the particle’s position Θ = k · r − ω t, where k and ω are the wavevector and frequency of the perturbation, r is the EP position, and t is the time. A distinction is made between field perturbations that resonate with an aspect of the orbital motion and those that do not. Resonance occurs when the wave phase returns to its initial value in an integer multiple of an orbital period. Convective transport occurs when resonant particles experience an unvarying wave phase. Alternatively, multiple wave-particle resonances usually decorrelate the phase, resulting in diffusive transport. Large orbits increase the number of important resonances and can cause chaotic orbits even for relatively small amplitude waves. In contrast, in the case of non-resonant perturbations, orbital phase averaging reduces transport. Large field perturbations introduce additional effects, including nonlinear resonances at fractional values of the orbital motion. In summary, large orbits are a blessing and a curse: For non-resonant modes, orbit-averaging reduces transport but, for resonant transport, large orbits facilitate jumps across topological boundaries and enhance the number of important resonances.

中文翻译：

---

磁约束等离子体中高能粒子传输的机制

超热离子和电子出现在空间和聚变等离子体中。因为这些高能粒子 (EP) 具有很大的速度，所以 EP 轨道必然会显着偏离磁性表面。轨道由运动的守恒常数描述，这些常数定义了不同轨道类型的拓扑边界。不稳定性产生的电场和磁场扰动会扰乱粒子轨道，导致运动常数发生变化。与这些扰动相关的“踢”的统计数据决定了产生的跨场传输。本教程的一个统一主题是粒子位置 Θ = k · r − ω t 处扰动相位的重要性，其中 k 和 ω 是扰动的波矢和频率，r 是 EP 位置，t 是时间. 与轨道运动的一个方面共振的场扰动和不与轨道运动的一个方面共振的场扰动之间存在区别。当波相位以轨道周期的整数倍返回其初始值时，就会发生共振。当共振粒子经历不变的波相时，就会发生对流传输。或者，多个波粒共振通常会使相位去相关，从而导致扩散传输。大轨道会增加重要共振的数量，即使对于振幅相对较小的波，也会导致轨道混乱。相比之下，在非共振扰动的情况下，轨道相位平均会减少传输。大场扰动会引入额外的影响，包括在轨道运动的分数值处的非线性共振。总之，大轨道是福也是祸：