Variational Symplectic Integrator for Long-Time Simulations of the Guiding-Center Motion of Charged Particles in General Magnetic Fields

[摘要] A variational symplectic integrator for the guiding-center motion of charged particles in general magnetic fields is developed for long-time simulation studies of magnetized plasmas. Instead of discretizing the differential equations of the guiding-center motion, the action of the guiding-center motion is discretized and minimized to obtain the iteration rules for advancing the dynamics. The variational symplectic integrator conserves exactly a discrete Lagrangian symplectic structure, and has better numerical properties over long integration time, compared with standard integrators, such as the standard and variable time-step fourth order Runge-Kutta methods.

[发布日期] 2008-02-11

[学科分类] 原子、分子光学和等离子物理

[关键词] CHARGED PARTICLES;DIFFERENTIAL EQUATIONS;LAGRANGIAN FUNCTION;MAGNETIC FIELDS;RUNGE-KUTTA METHOD;SIMULATION Gyrokinetic Equations;Guiding-center Approximations;Numerical Methods;Numerical Simulation