Weighting schemes for charges and fields to control self-force in unstructured finite element Particle-in-Cell codes

摘要

Particle-in-Cell (PIC) is a powerful technique for simulating physical processes where discrete objects exert forces on each other. In the context of this talk we are examining electrostatic plasmas where the particles represent electrons or ions which are free to move around the system and the electric fields are defined on the mesh. While this talk focuses on electrostatics, the techniques discussed are generalizable to other domains. In traditional structured codes symmetry between the weighting operators which map the particles charge to the mesh and the electric field from the mesh back to the particle results in no self-force. In the unstructured finite element world the traditional approaches result in a self-force which causes a particle to push itself and to violate Newton's laws of motion.