Modern investigations of dynamical space plasma systems such as magnetically complicated topologies within the Earth's magnetosphere make great use of supercomputer models as well as spacecraft observations. Space plasma simulations can be used to investigate energy transfer, acceleration, and plasma flows on both global and local scales. Simulation of global magnetospheric dynamics requires spatial and temporal scales currently achievable through magnetohydrodynamics or hybrid-kinetic simulations, which approximate electron dynamics as a charge-neutralizing fluid. We introduce a novel method for Vlasov-simulating electrons in the context of a hybrid-kinetic framework in order to examine the energization processes of magnetospheric electrons. Our extension of the Vlasiator hybrid-Vlasov code utilizes the global simulation dynamics of the hybrid method whilst modelling snapshots of electron dynamics on global spatial scales and temporal scales suitable for electron physics. Our eVlasiator model is shown to be stable both for single-cell and small-scale domains, and the solver successfully models Langmuir waves and Bernstein modes. We simulate a small test-case section of the near-Earth magnetotail plasma sheet region, reproducing a number of electron distribution function features found in spacecraft measurements.

中文翻译：

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混合全局模型中电子的Vlasov模拟：eVlasiator方法

对动态空间等离子体系统的现代研究，例如地球磁层内的磁性复杂拓扑，都充分利用了超级计算机模型和航天器观测结果。空间等离子模拟可用于研究全局和局部尺度上的能量传递，加速度和等离子流。全球磁层动力学的模拟需要目前可通过磁流体动力学或混合动力学模拟实现的时空尺度，这种模拟将电子动力学近似为电荷中和流体。为了检查磁层电子的激发过程，我们引入了一种在混合动力学框架内对电子进行Vlasov模拟的新方法。我们对Vlasiator混合-Vlasov代码的扩展利用了混合方法的全局仿真动力学，同时在适用于电子物理学的全局空间尺度和时间尺度上对电子动力学的快照进行了建模。我们的eVlasiator模型对于单单元域和小范围域均显示稳定，并且求解器成功地对Langmuir波和Bernstein模式进行建模。我们模拟了近地磁尾等离子体片区域的一个小的测试用例部分，再现了航天器测量中发现的许多电子分布函数特征。求解器成功地对Langmuir波和Bernstein模式进行了建模。我们模拟了近地磁尾等离子体片区域的一个小的测试用例部分，再现了航天器测量中发现的许多电子分布函数特征。求解器成功地对Langmuir波和Bernstein模式进行了建模。我们模拟了近地磁尾等离子体片区域的一个小的测试用例部分，再现了航天器测量中发现的许多电子分布函数特征。