Plasma Physics (Physics/ECE/NE 922) Seminars
Events on Monday, October 19th, 2015
- The JET-ILW Pedestal and the Fate of the H-mode
- Time: 12:00 pm - 1:00 pm
- Place: 2241 Physics Bldg
- Speaker: David Hatch, Institute for Fusion Studies, UT Austin,
- Abstract: The tokamak H-mode is defined by a narrow insulating region—the pedestal—at the plasma edge where turbulence is suppressed and sharp pressure gradients develop. The properties of the pedestal largely determine the quality of confinement and are also closely connected to issues of heat exhaust and plasma material interaction. The pedestal is, therefore, at the center of the most pressing issues facing fusion energy. I will describe recent progress in understanding the dynamics of turbulence and transport in the singularly ITER-relevant JET-ILW (ITER-like wall) pedestal, where unexpected pedestal properties are responsible for a significant degradation in performance. Gyrokinetic simulations using the GENE code identify the microtearing mode to be the dominant transport mechanism in the pedestal. Nonlinear simulations demonstrate the capacity of microtearing turbulence to account for the observed experimental heat fluxes. The capabilities and insights developed in this work are used to infer possible consequences for pedestal properties on ITER, including the possibility that ITER may be in a pedestal regime foreign to present-day experiments.
- Host: UW