Distinct turbulence saturation regimes in stellarators

Abstract

In the complex 3D magnetic fields of stellarators, ion-temperature-gradient turbulence is shown to have two distinct saturation regimes, as revealed by petascale numerical simulations, and explained by a simple turbulence theory. The first regime is marked by strong zonal flows, and matches previous observations in tokamaks. The newly observed second regime, in contrast, exhibits small- scale quasi-two-dimensional turbulence, negligible zonal flows, and, surprisingly, a weaker heat flux scaling. Our findings suggest that key details of the magnetic geometry control turbulence in stellarators.

Erratum added to end

References in corpus (2)

• Understanding nonlinear saturation in zonal-flow-dominated ion temperature gradient turbulence
• Nonlinear growth of zonal flows by secondary instability in general magnetic geometry

Cited by in corpus (7)

• A New Optimized Quasihelically SymmetricStellarator
• Critical gradient turbulence optimization toward a compact stellarator reactor concept
• Comparison of local and global gyrokinetic calculations of collisionless zonal flow damping in quasi-symmetric stellarators
• On the scaling of ion and electron temperature gradient driven turbulence in slab geometry
• Gyrokinetic simulations in stellarators using different computational domains
• Enstrophy non-conservation and the forward cascade of energy in two-dimensional electrostatic magnetized plasma turbulence
• Exploring zonal flow mediated saturation on stellarators