Abstract
Vacuum resonant magnetic perturbations (RMP) applied to otherwise axisymmetric tokamak plasmas produce in general a combination of non-resonant effects that preserve closed flux surfaces (kink response) and resonant effects that introduce magnetic islands and/or stochasticity (tearing response). The effect of the plasma kink response on the linear stability and nonlinear transport of edge turbulence is studied using the gyrokinetic toroidal code GTC for a DIII-D plasma with applied n = 2 vacuum RMP. GTC simulations use the 3D equilibrium of DIII-D discharge 158103 (Nazikian et al 2015 Phys. Rev. Lett. 114 105002), which is provided by nonlinear ideal MHD VMEC equilibrium solver in order to include the effect of the plasma kink response to the external field but to exclude island formation at rational surfaces. Analysis using the GTC simulation results reveal no increase of growth rates for the electrostatic drift wave instability and for the electromagnetic kinetic-ballooning mode in the presence of the plasma kink response to the RMP. Furthermore, nonlinear electrostatic simulations show that the effect of the 3D equilibrium on zonal flow damping is very weak and found to be insufficient to modify turbulent transport in the electrostatic turbulence.
Original language | English |
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Article number | 016005 |
Journal | Nuclear Fusion |
Volume | 57 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2017 |
Funding
This research used resources of the Oak Ridge Leadership Computing Facility at Oak Ridge National Laboratory (DOE Contract No. DE-AC05-00OR22725), and the National Energy Research Scientific Computing Center (DOE Contract No. DE-AC02-05CH11231). This work is supported by General Atomics subcontract 4500055243, U.S. DOE theory grant DE-SC0010416 and DE-SC0013804, and by General Atomics collaboration agreement under DOE grant DE-FG03- z94ER54271 and by the U.S. DOE grant to the Princeton Plasma Physics Lab., award No. DE-AC02-09CH11466.
Keywords
- edge localized mode
- plasma
- resonant magnetic perturbation
- tokamak
- turbulence