Fluid Closure, Theory, Relations to Particle Pinches, Fluid Resonances
- Chalmers University of Technology and EURATOM-VR Association, S-41296 Gothenburg (Sweden)
- Bogoliubov Institute for Theoretical Physics, 03680 Kiev (Ukraine)
The fluid closure in a toroidal plasma is discussed. In particular the relation to particle and temperature pinches is considered. Implications for the radial growth of transport coefficients are given. A particularly significant effect of dissipative kinetic resonances is that they reduce particle pinches. This is shown both for a gyrofluid and a quasilinear kinetic model. In particular the fact that the ITG and Trapped electron modes are resonant modes and that the effect of dissipative kinetic resonanses is ignorable for impurities but not for main ions shows that the closure aspect in a fluid description and strongly nonlinear effects in a kinetic description are instrumental for a proper description of particle pinches. We assume here that only the ITG mode due to main ions is unstable. The ITG mode due to impurities would, of course, be sensitive to the resonance with impurities. This also addresses the question of sources in the Fokker-Planck equation. The point is that we need only to worry about resonant sources for the wave dynamics, since RF heating with phase velocity or NBI heating with beam velocity far from the drift waves will appear only as ideal heat sources. The difference in phase velocity between drift waves and RF waves is much larger than the difference in thermal velocity of main ions and typical impurity ions.
- OSTI ID:
- 21611736
- Journal Information:
- AIP Conference Proceedings, Vol. 1392, Issue 1; Conference: IFP-CNR-Chalmers workshop on nonlinear phenomena in fusion plasmas, Varenna (Italy), 8-10 Jun 2011; Other Information: DOI: 10.1063/1.3647229; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BEAM INJECTION HEATING
CHARGED-PARTICLE TRANSPORT
FOKKER-PLANCK EQUATION
ION TEMPERATURE
IONS
NEUTRAL ATOM BEAM INJECTION
NONLINEAR PROBLEMS
PHASE VELOCITY
PINCH EFFECT
PLASMA
PLASMA IMPURITIES
RESONANCE
TEMPERATURE GRADIENTS
TRAPPED ELECTRONS
WAVE PROPAGATION
BEAM INJECTION
CHARGED PARTICLES
DIFFERENTIAL EQUATIONS
ELECTRONS
ELEMENTARY PARTICLES
EQUATIONS
FERMIONS
HEATING
IMPURITIES
LEPTONS
PARTIAL DIFFERENTIAL EQUATIONS
PLASMA HEATING
RADIATION TRANSPORT
VELOCITY