Interpolation for momentum conservation in 3D toroidal gyrokinetic particle simulation of plasmas

A linear momentum conserving interpolation for the electric field in a three-dimensional toroidal particle-in-cell gyrokinetic plasma simulation in a tokamak configuration is found unstable due to the false divergence of E→×B→ flow of particles. A paradigm 8-point finite difference for interpolation of the radial electric field on the poloidal plane is proposed which stabilizes the simulation.