Dynamics of Magnetic Islands driven by Ballooning Turbulence

N. Dubuit (1) , O. Agullo (1) , M. Muraglia (1) , J Frank , X. Garbet (2) , P. Maget (3)

1 PIIM - Physique des interactions ioniques et moléculaires
2 IRFM - Institut de Recherche sur la Fusion par confinement Magnétique
3 CEA/DSM/DRFC - Association EURATOM-CEA

Magnetic island generation by remote ballooning turbulence close to the plasma edge is investigated through ux-driven 3D Reduced-MHD simulations. The various coupling mechanisms are investigated : mono-helicity nonlinear coupling, multi-helicity nonlinear coupling and linear toroidal coupling. The dominant process depends on the imposed heat ux driving the turbulence. The remote drive happens in two successive phases corresponding to dierent coupling paths. While an island is remotely generated in both phases, it is dominated by dierent mode numbers, or harmonics, and therefore has a dierent shape. The size of the generated island is found to be proportional to the imposed heat ux, without threshold. The shape of the island in the saturated regime also depends on the imposed heat ux, with a more distorted shape at low power levels.

Domaines: Physique des plasmas [physics.plasm-ph]

N. Dubuit, O. Agullo, M. Muraglia, J Frank, X. Garbet, et al.. Dynamics of Magnetic Islands driven by Ballooning Turbulence. 2020. ⟨hal-03030454v1⟩