Global and local gyrokinetic simulations of high-performance discharges in view of ITER

One of the key challenges for plasma theory and simulation in view of ITER is to enhance the understanding and predictive capability concerning high-performance discharges. This involves, in particular, questions about high-beta operation, ion temperature profile stiffness, and the physics of transport barriers. The goal of this contribution is to shed light on these issues by means of physically comprehensive ab initio simulations with the global gyrokinetic code GENE, applied to discharges in TCV, ASDEX Upgrade, and JET-with direct relevance to ITER.

[1]  A Bottino,et al.  Inductive current density perturbations to probe electron internal transport barriers in tokamaks. , 2005, Physical review letters.

[2]  F Jenko,et al.  System size effects on gyrokinetic turbulence. , 2010, Physical review letters.

[3]  J. Candy,et al.  Magnetic stochasticity in gyrokinetic simulations of plasma microturbulence. , 2010, Physical review letters.

[4]  Laurent Villard,et al.  Gyrokinetic simulations of turbulent transport , 2010 .

[5]  F. Jenko,et al.  Non-linear gyrokinetic simulations of microturbulence in TCV electron internal transport barriers , 2011 .

[6]  Charlson C. Kim,et al.  Comparisons and physics basis of tokamak transport models and turbulence simulations , 2000 .

[7]  C. C. Petty,et al.  Sizing up plasmas using dimensionless parametersa) , 2006 .

[8]  A. Bondeson,et al.  The CHEASE code for toroidal MHD equilibria , 1996 .

[9]  F. Jenko,et al.  Scale separation between electron and ion thermal transport. , 2008, Physical review letters.

[10]  Akira Hirose,et al.  Electromagnetic and kinetic effects on the ion temperature gradient mode , 1992 .

[11]  T. Fujita,et al.  Chapter 2: Plasma confinement and transport , 2007 .

[12]  F. Jenko,et al.  Extreme heat fluxes in gyrokinetic simulations: a new critical β. , 2013, Physical review letters.

[13]  J. Candy.  Beta scaling of transport in microturbulence simulations , 2005 .

[14]  Frank Jenko,et al.  Electron temperature gradient driven turbulence , 1999 .

[15]  W. Houlberg,et al.  Bootstrap current and neoclassical transport in tokamaks of arbitrary collisionality and aspect ratio , 1997 .

[16]  T. Goodman,et al.  Inward thermodiffusive particle pinch in electron internal transport barriers in TCV , 2006 .

[17]  M. Barnes,et al.  Direct multiscale coupling of a transport code to gyrokinetic turbulence codes , 2009, 0912.1974.

[18]  Alain J. Brizard,et al.  Foundations of Nonlinear Gyrokinetic Theory , 2007 .

[19]  F. Jenko,et al.  Gyrokinetic prediction of microtearing turbulence in standard tokamaks , 2012 .

[20]  F. Jenko,et al.  Gyrokinetic microinstabilities in ASDEX Upgrade edge plasmas , 2008 .

[21]  Laurent Villard,et al.  Clarifications to the limitations of the s-α equilibrium model for gyrokinetic computations of turbulence , 2009 .

[22]  C. Roach,et al.  Kinetic instabilities that limit β in the edge of a tokamak plasma: a picture of an H-mode pedestal. , 2011, Physical review letters.

[23]  J. Candy,et al.  Electron heat transport from stochastic fields in gyrokinetic simulationsa) , 2011 .

[24]  C. Giroud,et al.  The beta scaling of energy confinement in ELMy H-modes in JET , 2004 .

[25]  F. Jenko,et al.  Magnetic stochasticity and transport due to nonlinearly excited subdominant microtearing modes , 2013 .

[26]  W. Dorland,et al.  Micro-tearing modes in the mega ampere spherical tokamak , 2007, 1110.3277.

[27]  William McCay Nevins,et al.  Electromagnetic gyrokinetic simulations , 2004 .

[28]  Frank Jenko,et al.  Gyrokinetic turbulence simulations at high plasma beta , 2008 .

[29]  Y. Camenen,et al.  Linear stability analysis of microinstabilities in electron internal transport barrier non-inductive discharges , 2006 .

[30]  F Jenko,et al.  Origin of magnetic stochasticity and transport in plasma microturbulence. , 2012, Physical review letters.

[31]  E. Joffrin,et al.  The CRONOS suite of codes for integrated tokamak modelling , 2010 .

[32]  Laurent Villard,et al.  Nonlinear quasisteady state benchmark of global gyrokinetic codes , 2010 .

[33]  Z. Lin,et al.  Size scaling of turbulent transport in magnetically confined plasmas. , 2002, Physical review letters.

[34]  T. Tala,et al.  Experimental study of the ion critical-gradient length and stiffness level and the impact of rotation in the JET tokamak. , 2009, Physical review letters.

[35]  Frank Jenko,et al.  The global version of the gyrokinetic turbulence code GENE , 2011, J. Comput. Phys..

[36]  K. V. Karelsky,et al.  Subgrid-scale modeling for the study of compressible magnetohydrodynamic turbulence in space plasmas , 2014 .

[37]  Jeff M. Candy,et al.  The local limit of global gyrokinetic simulations , 2004 .

[38]  F. Jenko,et al.  Transport properties of finite-β microturbulence , 2010 .

[39]  N Hawkes,et al.  A key to improved ion core confinement in the JET tokamak: ion stiffness mitigation due to combined plasma rotation and low magnetic shear. , 2011, Physical review letters.

[40]  O. Sauter,et al.  Current density evolution in electron internal transport barrier discharges in TCV , 2008 .

[41]  F Jenko,et al.  Gyrokinetic microtearing turbulence. , 2011, Physical review letters.

[42]  L. Vermare,et al.  β dependence of micro-instabilities using linear gyrokinetic simulations , 2008 .

[43]  Jeff M. Candy,et al.  Beta scaling of transport on the DIII-D Tokamak: Is transport electrostatic or electromagnetic? , 2004 .