18th Technical Meeting on Energetic Particles in Magnetic Confinement Systems

Global Gyrokinetic Simulations of Reversed Shear Alfven Eigenmode Driven by Energetic Particle in DIII-D plasmas

Not scheduled

20m

Poster Multiscale Physics and Instabilities involving Energetic Particles in Burning Plasmas

Speaker

Pengfei Liu (Institute of Physics, Chinese Academy of Sciences)

Description

Alfven eigenmodes (AE) driven by energetic particles (EP) can cause large EP transport that degrades plasma confinement and threaten machine integrity. Understanding the nonlinearly saturated AE amplitude and associated EP transport level is needed for extrapolating EP confinement properties to burning plasma experiments such as ITER.

Global gyrokinetic simulations find strong zonal fields (ZFs) generated by reversed shear Alfven eigenmodes (RSAE) dominate the RSAE nonlinear saturation in DIII-D plasma. The radial profile of ZFs agrees well with analytic expression, and the effects of ZFs on the EP’s drive are investigated [Nuclear Fusion 65, 016018 (2024)]. Global gyrokinetic simulations coupling meso-scale RSAE and micro-scale ion temperature gradient (ITG) microturbulence find the regulation of RSAE by ITG results in quasi-steady state AE turbulence that is comparable to experimental measurements [Phys. Rev. Lett. 128, 185001(2022)]. In turn, stronger zonal flows generated by RSAE reduce thermal ion heat transport driven by ITG [Nuclear Fusion 64, 076007 (2024)]. For a stronger background ITG, the regulation of the RSAE by the ITG is stronger, while the RSAE effects on the ITG are weaker.