Artemyev A V, Neishtadt A I, Vasiliev A A, Mourenas D
Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California, USA.
Space Research Institute, Moscow, Russia.
Phys Rev E. 2017 Feb;95(2-1):023204. doi: 10.1103/PhysRevE.95.023204. Epub 2017 Feb 3.
In this paper we provide a theoretical model describing the evolution of the charged-particle distribution function in a system with nonlinear wave-particle interactions. Considering a system with strong electrostatic waves propagating in an inhomogeneous magnetic field, we demonstrate that individual particle motion can be characterized by the probability of trapping into the resonance with the wave and by the efficiency of scattering at resonance. These characteristics, being derived for a particular plasma system, can be used to construct a kinetic equation (or generalized Fokker-Planck equation) modeling the long-term evolution of the particle distribution. In this equation, effects of charged-particle trapping and transport in phase space are simulated with a nonlocal operator. We demonstrate that solutions of the derived kinetic equations agree with results of test-particle tracing. The applicability of the proposed approach for the description of space and laboratory plasma systems is also discussed.
在本文中，我们提供了一个理论模型，用于描述具有非线性波粒相互作用的系统中带电粒子分布函数的演化。考虑到一个在非均匀磁场中传播强静电波的系统，我们证明了单个粒子的运动可以通过陷入与波共振的概率以及共振时的散射效率来表征。这些针对特定等离子体系统得出的特性，可用于构建一个动力学方程（或广义福克 - 普朗克方程），以模拟粒子分布的长期演化。在这个方程中，带电粒子在相空间中的捕获和输运效应通过一个非局部算符来模拟。我们证明了所推导动力学方程的解与测试粒子追踪的结果一致。还讨论了所提出方法在描述空间和实验室等离子体系统方面的适用性。
