Turbulence Mechanisms of Enhanced Performance Stellarator Plasmas
P. Xanthopoulos, S. Bozhenkov, M. Beurskens, H. M. Smith, G. G. Plunk, P. Helander, C. D. Beidler, J. A. Alcusón, A. Alonso, A. Dinklage, O. Ford, G. Fuchert, J. Geiger, J. H. E. Proll, M. J. Pueschel, Y. Turkin, F. Warmer, the W7-X Team
Abstract
We theoretically assess two mechanisms thought to be responsible for the enhanced performance observed in plasma discharges of the Wendelstein 7-X stellarator experiment fueled by pellet injection. The effects of the ambipolar radial electric field and the electron density peaking on the turbulent ion heat transport are separately evaluated using large-scale gyrokinetic simulations. The essential role of the stellarator magnetic geometry is demonstrated, by comparison with a tokamak.
Topics & Concepts
StellaratorAmbipolar diffusionPlasmaTokamakTurbulencePhysicsWendelstein 7-XGyrokineticsElectric fieldAtomic physicsMagnetic fieldIonElectron temperatureComputational physicsNuclear physicsMechanicsQuantum mechanicsMagnetic confinement fusion researchIonosphere and magnetosphere dynamicsLaser-Plasma Interactions and Diagnostics