Effects of anisotropic energetic particles on zonal flow residual level

Abstract In tokamak plasmas, the interaction among micro-turbulence, zonal flows (ZFs) and energetic particles (EPs) can affect turbulence saturation level consequent confinement quality thus, is important for future burning plasmas. this work, EP anisotropy effects on ZF residual are studied by using anisotropic distributions with dependence pitch. Significant long wavelength ZFs have been found when small to moderate width around dominant pitch in distribution function assumed. addition, it that enhanced barely passing/trapped and/or deeply trapped EPs, but suppressed well passing intermediate EPs. Numerical calculation shows ASDEX Upgrade typical functions bring −3% +5.5% mitigation/enhancement level, depending functions.