Ion temperature gradient mode mitigation by energetic particles, mediated by forced-driven zonal flows

Abstract

In this work, we use the global electromagnetic and electrostatic gyro kinetic approaches to investigate the effects of zonal flows forced-driven by Alfvén modes due to their excitation by energetic particles on the dynamics of ITG (ion temperature gradient) instabilities. The equilibrium of the 92416 JET tokamak shot is considered. The linear, nonlinear Alfvén modes, and the zonal flow dynamics are investigated, and their respective radial structures and saturation levels are reported. ITG dynamics in the presence of the zonal flows excited by these Alfvén modes are also investigated. The zonal flows forced-driven by Alfvén modes can significantly impact the ITG dynamics. A zonal flow amplitude scan reveals the existence of an inverse relation between the zonal flow amplitude and the ITG growth rate. These results indicate that forced-driven zonal flows can be an important indirect part of turbulence mitigation due to the injection of energetic particles.