标题： 探索强磁化带电粒子运动的指数时间积分方法 显示英文标题

标题： Exploring exponential time integration for strongly magnetized charged particle motion

摘要： 在等离子体物理的粒子模拟（PIC）中，一个基本任务是求解带电粒子在电磁场中的运动，当等离子体强烈磁化时，由于回旋运动和系统整体宏观行为的时间尺度存在巨大差异而产生的数值刚性问题，使得该问题尤为具有挑战性。 与传统的有限差分方案不同，我们研究了指数积分技术来数值模拟强磁化带电粒子的运动。 对于均匀磁场下的数值实验表明，指数积分器在处理线性问题（即由二次电标量势确定电场的配置）时表现出色，并且在具有三次和四次电标量势的非线性问题上，其性能与传统方法相当。 显示英文摘要

摘要： A fundamental task in particle-in-cell (PIC) simulations of plasma physics is solving for charged particle motion in electromagnetic fields. This problem is especially challenging when the plasma is strongly magnetized due to numerical stiffness arising from the wide separation in time scales between highly oscillatory gyromotion and overall macroscopic behavior of the system. In contrast to conventional finite difference schemes, we investigated exponential integration techniques to numerically simulate strongly magnetized charged particle motion. Numerical experiments with a uniform magnetic field show that exponential integrators yield superior performance for linear problems (i.e. configurations with an electric field given by a quadratic electric scalar potential) and are competitive with conventional methods for nonlinear problems with cubic and quartic electric scalar potentials.