A gyrokinetic electron and fully kinetic ion plasma simulation model

Abstract

A novel new kinetic simulation model has been developed to investigate dynamics in collisionless plasmas. In this model, the electrons are treated as gyrokinetic (GK) particles and ions are treated as fully kinetic (FK) particles. In the GK-electron and FK-ion (GKe/FKi) plasma simulation model, the rapid electron cyclotron motion is removed, while keeping finite electron Larmor radii, realistic electron-to-ion mass ratio, wave–particle interactions, and off-diagonal components of the electron pressure tensor. The model is particularly suitable for plasma dynamics with wave frequencies lower than the electron gyrofrequency, and for problems in which the wave modes ranging from Alfvén waves to lower-hybrid/whistler waves need to be handled on an equal footing. Using this model, the computation power can be significantly improved over that of the existing full-particle codes. The GKe/FKi model, furthermore, can also handle physics with realistic electron-to-ion mass ratio and dynamic processes on the global Alfvén time/spatial scales. With respect to the hybrid (i.e. FK ion and fluid electron) model, the GKe/FKi model has the advantage that important electron kinetic physics, such as wave–particle resonances and finite electron Larmor radius effects, are included. The simulation model has been successfully benchmarked for linear waves in uniform plasmas against analytic dispersion relation.