Kinetic, two-fluid and MHD simulations of plasmas

Jukka A. Heikkinen (Corresponding Author), J. Lönnroth

Research output: Contribution to journalArticleScientificpeer-review

3 Citations (Scopus)

Abstract

The kinetic and extended magnetohydrodynamic (MHD) simulation methods are discussed in the context of their ability to simulate macroscopic plasma evolution on an MHD evolution time scale with microturbulence in toroidal magnetized plasmas. To properly model the evolution of neoclassical equilibrium, it is important to use full-f gyrokinetic calculation with sufficient accuracy for perpendicular viscosity. Similarly in MHD problems, a good accuracy in constructing the closures, in particular for the viscosity stress elements, is required. Although evidence of spontaneous reduction of transport with the consequent rapid steepening of the pressure gradient is found in simulations with full-f 5D gyrokinetic and 3D Braginskii fluid equations, no simulation of the transport barrier formation in agreement with experimental observations has yet been presented. For a comprehensive description of edge plasma dynamics, including L-H transition, pedestal formation, and ELM oscillation problems, full-f 5D gyrokinetic simulation is a necessity, at least in hybrid with 3D MHD. With present-day computers, the global transport time scale can be reached with full-f gyrokinetic simulations in small tokamaks (ñ* [less-than or equal to] 50-100), while fluid simulation has to be used for MHD evolution time scale in medium-sized tokamaks.
Original languageEnglish
Pages (from-to)B465-B477
JournalPlasma Physics and Controlled Fusion
Volume49
Issue number12B
DOIs
Publication statusPublished - 2007
MoE publication typeA1 Journal article-refereed

Fingerprint

magnetohydrodynamic simulation
Magnetohydrodynamics
magnetohydrodynamics
Plasmas
Kinetics
Fluids
fluids
kinetics
simulation
Viscosity
viscosity
plasma dynamics
toroidal plasmas
Pressure gradient
pressure gradients
closures
oscillations

Keywords

  • MHD
  • magnetohydrodynamic simulation
  • JET
  • Tokamak
  • ITER
  • fusion energy
  • fusion reactors
  • plasma

Cite this

Heikkinen, Jukka A. ; Lönnroth, J. / Kinetic, two-fluid and MHD simulations of plasmas. In: Plasma Physics and Controlled Fusion. 2007 ; Vol. 49, No. 12B. pp. B465-B477.
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abstract = "The kinetic and extended magnetohydrodynamic (MHD) simulation methods are discussed in the context of their ability to simulate macroscopic plasma evolution on an MHD evolution time scale with microturbulence in toroidal magnetized plasmas. To properly model the evolution of neoclassical equilibrium, it is important to use full-f gyrokinetic calculation with sufficient accuracy for perpendicular viscosity. Similarly in MHD problems, a good accuracy in constructing the closures, in particular for the viscosity stress elements, is required. Although evidence of spontaneous reduction of transport with the consequent rapid steepening of the pressure gradient is found in simulations with full-f 5D gyrokinetic and 3D Braginskii fluid equations, no simulation of the transport barrier formation in agreement with experimental observations has yet been presented. For a comprehensive description of edge plasma dynamics, including L-H transition, pedestal formation, and ELM oscillation problems, full-f 5D gyrokinetic simulation is a necessity, at least in hybrid with 3D MHD. With present-day computers, the global transport time scale can be reached with full-f gyrokinetic simulations in small tokamaks ({\~n}* [less-than or equal to] 50-100), while fluid simulation has to be used for MHD evolution time scale in medium-sized tokamaks.",
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Kinetic, two-fluid and MHD simulations of plasmas. / Heikkinen, Jukka A. (Corresponding Author); Lönnroth, J.

In: Plasma Physics and Controlled Fusion, Vol. 49, No. 12B, 2007, p. B465-B477.

Research output: Contribution to journalArticleScientificpeer-review

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AB - The kinetic and extended magnetohydrodynamic (MHD) simulation methods are discussed in the context of their ability to simulate macroscopic plasma evolution on an MHD evolution time scale with microturbulence in toroidal magnetized plasmas. To properly model the evolution of neoclassical equilibrium, it is important to use full-f gyrokinetic calculation with sufficient accuracy for perpendicular viscosity. Similarly in MHD problems, a good accuracy in constructing the closures, in particular for the viscosity stress elements, is required. Although evidence of spontaneous reduction of transport with the consequent rapid steepening of the pressure gradient is found in simulations with full-f 5D gyrokinetic and 3D Braginskii fluid equations, no simulation of the transport barrier formation in agreement with experimental observations has yet been presented. For a comprehensive description of edge plasma dynamics, including L-H transition, pedestal formation, and ELM oscillation problems, full-f 5D gyrokinetic simulation is a necessity, at least in hybrid with 3D MHD. With present-day computers, the global transport time scale can be reached with full-f gyrokinetic simulations in small tokamaks (ñ* [less-than or equal to] 50-100), while fluid simulation has to be used for MHD evolution time scale in medium-sized tokamaks.

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