Abstract
We report the first observation of localized modulation of turbulent density fluctuations ñ (via beam emission spectroscopy) by neoclassical tearing modes (NTMs) in the core of the DIII-D tokamak. NTMs are important as they often lead to severe degradation of plasma confinement and disruptions in high-confinement fusion experiments. Magnetic islands associated with NTMs significantly modify the profiles and turbulence drives. In this experiment ñ was found to be modulated by 14% across the island. Gyrokinetic simulations suggest that ñ could be dominantly driven by the ion temperature gradient instability.
| Original language | English |
|---|---|
| Article number | 215001 |
| Journal | Physical Review Letters |
| Volume | 116 |
| Issue number | 21 |
| DOIs | |
| State | Published - May 26 2016 |
| Externally published | Yes |
Funding
This work was supported in part by the U.S. Department of Energy under DE-FG02-08ER54984, DE-FG03-86ER53266, and DE-FC02-04ER54698. The gyrokinetic simulations presented in this work used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No.DE-AC02-05CH11231.