An Efficient BOR-FDTD-PIC Algorithm for Time-Domain Simulation of Axisymmetric Plasma Radiation

This paper introduces a novel Body-of-Revolution Particle-In-Cell Finite-Difference Time-Domain (BOR-PIC-FDTD) method for accurate and efficient modeling the self-consistent interactions between axisymmetric charged particles and self-generated electromagnetic fields. By rigorously leveraging axial symmetry, the proposed method effectively maps the 3D electromagnetic problem onto a computationally efficient two-dimensional (r-z) formulation, significantly lowering memory consumption and computational complexity. Within this framework, Maxwell’s equations are explicitly solved using the BOR-FDTD scheme, with special numerical treatments based on the loop theorem implemented to mitigate singular behavior at the symmetry axis (r = 0). Superparticle represents a ring uniformly distributed charged particle, and its intersection with the r-z plane is the superparticle position. To ensure strict charge conservation, we extend the zigzag current deposition scheme to the BOR coordinates, precisely interpolating particle-generated current densities onto the BOR-FDTD grid. Validated through unified benchmarks and convergence studies, numerical examples demonstrate that the proposed BOR-PIC-FDTD method maintains high consistency with CST and BOR-PIC++ results while enabling a more straightforward implementation and reduced memory/runtime footprints. Finally, a full-dynamics simulation of plasma plume diffusion in vacuum demonstrates the practicality of the proposed method.