Multiple Boris solvers for particle-in-cell (PIC) simulation

 Particle-in-cell (PIC) simulation has long been used in theoretical plasma physics. In PIC simulation, the Boris solver is the de-facto standard for solving particle motion, and it has been used over a half century. Meanwhile, there is a continuous demand for better particle solvers. In this contribution, we introduce a family of Boris-type schemes for integrating the motion of charged particles. We call the new solvers the multiple Boris solvers. The new solvers essentially repeat the standard two-step procedure multiple times in the Lorentz-force part, and we derive a single-step form for arbitrary subcycle number n. The new solvers give n² times smaller errors, allow larger timesteps, but they are computationally affordable for moderate n. The multiple Boris solvers also reduce a numerical error in long-term plasma motion in a relativistic magnetized flow.

Reference:

• S. Zenitani & T. N. Kato, Multiple Boris integrators for particle-in-cell simulation, Comput. Phys. Commun. 247, 106954, doi:10.1016/j.cpc.2019.106954 (2020)