A New Gauge-Compatible Finite Element PIC Algorithm on an Unstructured Mesh

We develop and study various aspects of a new structure-preserving particle-in-cell algorithm. Applying the formalism of finite element exterior calculus, our study extends a previously developed gauge-compatible canonical Hamiltonian PIC method [J. Plasma Phys. 86, 835860303 (2020)] to an unstructured mesh. We derive the momentum map of this new algorithm and its corresponding exact charge conservation law. We further describe its scaling to whole-device tokamak simulation. Our study is oriented toward PIC development suitable for the new generation of exascale supercomputers.