Electromagnetic turbulence in tokamak plasmas

Circular large-aspect-ratio tokamak

Zonal flow saturation (turbulent eddies “destroyed” by the sheared flow)
Electrostatic potential (poloidal cross-section) for EM ITG: $\beta_{ORB}=0.00052$ ($\beta = 0.208\%$)

Saturation through profile evolution (turbulence “expelled” out of simulation domain)
Electrostatic potential (poloidal cross-section) for KBM: $\beta_{ORB}=0.0052$ ($\beta = 2.08\%$)

ASDEX-Upgrade geometry (down-scaled $L_{{\rm x}} = 300$)

Safety factor; poloidal cross-section (turbulence at $\beta=1.6\%$)

Temperature and density profiles

EM-ITG regime (stabilization by $\beta$); energy flux for $\beta_{ORB5} = 0.004$ ($\beta = 1.6\%$)

Electrostatic potential evolution (poloidal cross-section) for $\beta_{ORB5} = 0.00054$ ($\beta=0.216\%$)
Electrostatic potential evolution (poloidal cross-section) for $\beta_{ORB5} = 0.004$ ($\beta=1.6\%$)

ITER geometry (down-scaled)

Electrostatic potential (poloidal cross-section): $\beta_{ORB} = 0.001$ ($\beta = 0.4\%$)