Particle acceleration in collisionless plasma systems is a central question in astroplasma and astroparticle physics. The structure of the acceleration regions, electron-ion energy equilibration, preacceleration of particles at shocks to permit further energization by diffusive shock acceleration, require knowledge of the distribution function of particles besides the structure and dynamic of electromagnetic fields, and hence a kinetic description is desirable. Particle-in-cell simulations offer an appropriate, if computationally expensive method of essentially conducting numerical experiments that explore kinetic phenomena in collisionless plasma. We review recent results of PIC simulations of astrophysical plasma systems, particle acceleration, and the instabilities that shape them.

中文翻译：

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宇宙辐射和等离子体不稳定性的 PIC 模拟方法

无碰撞等离子体系统中的粒子加速是天体等离子体和天体粒子物理学的核心问题。加速区的结构、电子-离子能量平衡、粒子在冲击时的预加速以允许通过扩散冲击加速进一步激发能量，除了电磁场的结构和动力学外，还需要了解粒子的分布函数，因此动力学描述是可取。细胞内粒子模拟提供了一种适当的、但计算成本高的方法，该方法主要进行数值实验，探索无碰撞等离子体中的动力学现象。我们回顾了天体物理等离子体系统、粒子加速和塑造它们的不稳定性的 PIC 模拟的最新结果。