Non-linear magnetohydrodynamic simulations of density evolution in Tore Supra sawtoothing plasmas
- CEA, IRFM, F-13108 Saint-Paul-Lez-Durance (France)
- Centre de Physique Theorique, Ecole Polytechnique, CNRS, F-91128 Palaiseau Cedex (France)
- Aix-Marseille University, IIFS-PIIM, UMR 7345, F-13397 Marseille (France)
The plasma density evolution in sawtooth regime on the Tore Supra tokamak is analyzed. The density is measured using fast-sweeping X-mode reflectometry which allows tomographic reconstructions. There is evidence that density is governed by the perpendicular electric flows, while temperature evolution is dominated by parallel diffusion. Postcursor oscillations sometimes lead to the formation of a density plateau, which is explained in terms of convection cells associated with the kink mode. A crescent-shaped density structure located inside q = 1 is often visible just after the crash and indicates that some part of the density withstands the crash. 3D full MHD nonlinear simulations with the code XTOR-2F recover this structure and show that it arises from the perpendicular flows emerging from the reconnection layer. The proportion of density reinjected inside the q = 1 surface is determined, and the implications in terms of helium ash transport are discussed.
- OSTI ID:
- 22068886
- Journal Information:
- Physics of Plasmas, Vol. 19, Issue 11; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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