Electromagnetic gyrokinetic-ion drift-fluid-electron hybrid simulation Original Research Article

Progress on gyrokinetic-ion drift-fluid-electron hybrid simulation is reported. Simulation results are shown from a three-dimensional toroidal electromagnetic simulation using field-line-following coordinates. It is found that for β≳1.5% there is strong destabilization of Alfvénic ion-temperature-gradient (ITG) driven instabilities. Nonlinear results show a corresponding increase in the the ion heat flux. Secondly, we report very good parallel performance and near perfect scalability was shown on the Cray T3E and SGI O2K using a one-dimensional domain decomposition and digital filtering to handle the shift at the boundary along the magnetic field-line due to toroidal boundary conditions. Finally, we report recent results in the electrostatic limit, which explore a scheme to reduce the heat flux by adding a ripple to the ion temperature profile. Both self-generated and equilibrium Er shear flows are included for the first time. It may be possible to achieve similar results experimentally using ion cyclotron resonance heating.