Revision 1

Accepted · first revision · record

Title: How far 3D shaping can reduce turbulent transport
Plain: Optimized stellarators have nearly eliminated collisional heat loss, so turbulence now dominates. How much turbulence can be reduced just by choosing the magnetic shape is unknown.
Precise: In W7-X, ion-temperature-gradient turbulence clamps the ion temperature near 1.5 keV in electron-heated plasmas unless the density profile is peaked. Determine the minimum nonlinear gyrokinetic ion heat flux at fixed normalized gradients achievable by 3D shaping, using nonlinear gyrokinetics inside the optimization loop, and validate the predicted reduction experimentally. An answer is the attainable reduction factor relative to W7-X at fixed gradients.
Settled by: An optimized configuration whose predicted turbulence reduction is confirmed in a new or modified stellarator experiment.
Kind: well-posed
Answer type: value
References: (empty)
Literature status: open
Status note: (empty)
Posed since: (empty)