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Modelling of the Radial Electric Field in the ASDEX Upgrade Ohmic Shots
Author(s) -
Rozhansky V.,
Kaveeva E.,
Voskoboynikov S.,
Coster D. P.
Publication year - 2008
Publication title -
contributions to plasma physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.531
H-Index - 47
eISSN - 1521-3986
pISSN - 0863-1042
DOI - 10.1002/ctpp.200810012
Subject(s) - collisionality , asdex upgrade , electric field , physics , joule heating , mechanics , tokamak , turbulence , toroid , ohmic contact , field (mathematics) , computational physics , atomic physics , plasma , nuclear physics , electrode , quantum mechanics , mathematics , pure mathematics
Several ASDEX‐Upgrade Ohmic shots with different densities and temperatures corresponding to different collisionality regimes at the separatrix were simulated with transport code B2SOLPS5.0. The expression for the parallel viscosity was extended to be consistent with the neoclassical electric field in all collisionality regimes including plateau and banana regimes. It is demonstrated that for all shots in the core region deeper than the viscous layer (of the order of 1 cm inside the separatrix) the relation between the radial electric field, parallel velocity, density and temperature gradients is close to the neoclassical one. This is consistent with the results of many simulations performed earlier for the collisional regimes. The contribution from the toroidal velocity, which is generated in the SOL and transported further to the core, to the radial electric field profile is found to be modest and comparable with density and temperature gradient contribution. The simulation results do not reproduce the dependence of the poloidal velocity of the turbulence on the collisionality measured in [1] deep inside the core. On the other hand, the shape of the radial electric field in the separatrix vicinity both inside and outside the separatrix is consistent with the measured poloidal rotation velocity of the turbulence. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)