Abstract Energetic particles interacting with interplanetary or interstellar plasmas experience transport along and across large scale magnetic fields. In particular the diffusion of particles in the perpendicular direction is difficult to understand theoretically. However, significant progress has been achieved due to the development of test-particle simulations, non-linear systematic theories, and heuristic descriptions of the transport. Non-linear analytical theories often work well but in some cases they require to incorporate a correction factor a 2 in order to achieve perfect agreement with simulations. It was stated previously that a 2 ≈ 1 / 3 but there are also cases where a 2 ≈ 1 was found meaning that no correction factor is needed. It is the purpose of this paper to present comprehensive test-particle simulations for slab/2D turbulence also known as two-component turbulence. We consider a wide range of parameters and perform 48 different runs. In all cases we compare our numerical findings with analytical theories in order to determine the exact value of a 2 for each case. We also discuss the physical meaning of a 2 which should eventually lead to further improvements of analytical theories for perpendicular transport.

中文翻译：

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高能粒子与磁化等离子体相互作用的详细测试粒子模拟 I. 双分量湍流

摘要 与行星际或星际等离子体相互作用的高能粒子会经历沿和跨越大尺度磁场的传输。特别是粒子在垂直方向上的扩散在理论上是难以理解的。然而，由于测试粒子模拟、非线性系统理论和输运启发式描述的发展，已经取得了重大进展。非线性分析理论通常工作得很好，但在某些情况下，它们需要包含校正因子 a 2 以实现与模拟的完美一致。之前说过 a 2 ≈ 1 / 3 但也有发现 a 2 ≈ 1 意味着不需要校正因子的情况。本文的目的是展示板片/2D 湍流（也称为双分量湍流）的综合测试粒子模拟。我们考虑了广泛的参数并执行了 48 次不同的运行。在所有情况下，我们将我们的数值发现与分析理论进行比较，以确定每种情况下 2 的确切值。我们还讨论了 2 的物理意义，这最终会导致垂直输运分析理论的进一步改进。