Impact of three-dimensional magnetic perturbations on turbulence in tokamak edge plasmas

The impact of resonant magnetic perturbations (RMPs) on the plasma edge equilibrium and on the turbulence is investigated in a circular limited configuration. The study is based on a Braginski-based isothermal fluid model. The flow response of an unperturbed case to a small amplitude three-dimensional single mode RMP is studied and a scan in amplitude and poloidal and toroidal mode number is performed. Special attention is given when magnetic islands appear in the simulation domain on flux surfaces of rational safety factor. Results show an impact of magnetic perturbations (MPs) on both the plasma equilibrium and on the turbulence properties, with a deviation to the reference solution which depends on the MPs amplitude and on their wavenumbers. The impact of MPs on turbulence is however globally weaker than on the plasma equilibrium, suggesting a stabilizing effect of the MP on turbulent transport. Experimental trends are recovered such as the density pump-out and the increase of the radial electric field as well as the reorganization of the parallel velocity. The ballooning of the transport is modified under the effect of the perturbations, with a shift of the peaked poloidal region from the upper to the lower outer midplane. In the present model, the SOL width is observed decreasing in the presence of MPs. Turbulence properties are also impacted with the density fluctuations level decreasing in perturbed solutions and the intermittency is globally weakened.

[1]  V. Rozhansky,et al.  Physics basis for the first ITER tungsten divertor , 2019, Nuclear Materials and Energy.

[2]  P. Ghendrih,et al.  Tokamak Edge Plasma Turbulence Interaction with Magnetic X-Point in 3D Global Simulations , 2019, Fluids.

[3]  W. Ding,et al.  Investigation of RMP induced density pump-out on EAST , 2018, Nuclear Fusion.

[4]  N. Fedorczak,et al.  Turbulent heat transport in TOKAM3X edge plasma simulations , 2018, Contributions to Plasma Physics.

[5]  W. Suttrop,et al.  ELM divertor peak energy fluence scaling to ITER with data from JET, MAST and ASDEX upgrade , 2017 .

[6]  T. Ribeiro,et al.  Gyrofluid computation of magnetic perturbation effects on turbulence and edge localized bursts , 2016, 1612.04121.

[7]  Guido Ciraolo,et al.  The TOKAM3X code for edge turbulence fluid simulations of tokamak plasmas in versatile magnetic geometries , 2016, J. Comput. Phys..

[8]  T. Evans,et al.  Exploration of magnetic perturbation effects on advanced divertor configurations in NSTX-U , 2016 .

[9]  G. Saibene,et al.  Three-dimensional modeling of plasma edge transport and divertor fluxes during application of resonant magnetic perturbations on ITER , 2016 .

[10]  T. Evans.  Resonant magnetic perturbations of edge-plasmas in toroidal confinement devices , 2015 .

[11]  A. Leonard.  Edge-localized-modes in tokamaksa) , 2014 .

[12]  Masahiro Kobayashi,et al.  Recent Improvements in the EMC3‐Eirene Code , 2014 .

[13]  J. Contributors,et al.  Scaling of the tokamak near the scrape-off layer H-mode power width and implications for ITER , 2013 .

[14]  Yueqiang Liu,et al.  The effect of resonant magnetic perturbations on the divertor heat and particle fluxes in MAST , 2013, 1307.2485.

[15]  J. Contributors,et al.  Outer target heat fluxes and power decay length scaling in L-mode plasmas at JET and AUG , 2013 .

[16]  A. Loarte,et al.  Screening of resonant magnetic perturbations by flows in tokamaks , 2012 .

[17]  J. Coenen,et al.  Rotation and radial electric field in the plasma edge with resonant magnetic perturbation at TEXTOR , 2011 .

[18]  A. Kirk,et al.  Edge turbulence and flows in the presence of resonant magnetic perturbations on MAST , 2010 .

[19]  D. Reiser,et al.  Plasma currents induced by resonant magnetic field perturbations in tokamaks , 2009 .

[20]  J. S. deGrassie,et al.  RMP ELM suppression in DIII-D plasmas with ITER similar shapes and collisionalities , 2008 .

[21]  Dirk Reiser,et al.  Impact of large island perturbations on turbulent blob transport in tokamaks , 2007 .

[22]  X. Garbet,et al.  Electrostatic turbulence and transport with stochastic magnetic field lines , 2002 .

[23]  Y. Sarazin,et al.  Intermittent particle transport in two-dimensional edge turbulence , 1998 .

[24]  E. Doyle,et al.  Effects of resonant magnetic perturbations on turbulence and transport in DIII-D L-mode plasmas , 2015 .

[25]  X. Garbet,et al.  Non-linear MHD modeling of edge localized mode cycles and mitigation by resonant magnetic perturbations , 2014 .

[26]  P. Stangeby,et al.  The Plasma Boundary of Magnetic Fusion Devices , 2000 .