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- Ivonin, Igor A.
(författare)
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Global Turbulent EquiPartition (TEP) in Tokamak Plasma
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- We studied analytically and numerically the establishment of global turbulent equipartition (TEP) of magnetised electrons in a tokamak plasma. This allows us to investigate self-consistently the inhomogeneous distributions of the plasma density, the electron and the ion temperatures, the generation of radial electric field and the poloidal and the toroidal rotation in the turbulent tokamak plasma. We have obtained the level and the inhomogeneous distribution of the turbulent energy, which allows us to estimate the rate of turbulent mixing at any point in a tokamak. We have used the invariant kinetic description for the electrons and semi hydrodynamics approach for the ions (separately for the trapped and passing ions) to describe the TEP state of the plasma in tokamak. As a result, we found two qualitatively different TEP distributions, that am similar to the L and H-modes in tokamak. We have studied these modes in details. We have got the scaling laws of the density and the temperature in both cases. We have found that, in both cases, the turbulence level is sufficiently large to provide the quick rate of the turbulent mixing in the central tokamak region, which is required for the validity of the global TEP approach. We have found that, in the second case of H-mode, the turbulent suppression zone, the poloidal rotation and the negative radial electric field is developed at the plasma boundary. The turbulence level in the turbulence suppression zone, which appears in the H-mode, is rather- small to provide quick turbulent mixing in this region. It means, that two different TEPS, one for the hot central plasma and another one for the cold plasma at the separatrix could appear outside the turbulence suppression zone. We have studied this coexistence by using different models.
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