Transport barrier for the radial diffusion due to the ExB drift motion of guiding centers in cylindrical confinement geometry

Olivier Izacard (1, 2) , Natalia Tronko (1, 2) , Cristel Chandre (1, 2) , Guido Ciraolo (3) , Michel Vittot (1, 2) , Philippe Ghendrih (4)

1 CPT - Centre de Physique Théorique - UMR 6207
2 CPT - Centre de Physique Théorique - UMR 7332
3 M2P2 - Modélisation et Simulation Numérique (en mécanique des fluides)
4 IRFM - Institut de Recherche sur la Fusion par confinement Magnétique

We consider the radial transport of test particles due to the ExB drift motion in the guiding center approximation. In a configuration where the magnetic field is constant and uniform in linear devices or with neglecting toroidal effects in tokamaks, the ExB instability is one of the main sources of deconfinement of magnetized plasmas. Using an explicit expression to modify the electrostatic potential, we show that it is possible to construct a transport barrier which suppresses the radial transport. We propose an algorithm and a simulation of test particles for the implementation of this local modification computed from an electrostatic potential known on a spatio-temporal grid. The number of particles which escape the inner region defined by the barrier measures the efficiency of the control.

Domaines: Physique des plasmas [physics.plasm-ph]; Dynamique Chaotique [nlin.CD]

Olivier Izacard, Natalia Tronko, Cristel Chandre, Guido Ciraolo, Michel Vittot, et al.. Transport barrier for the radial diffusion due to the ExB drift motion of guiding centers in cylindrical confinement geometry. 2010. ⟨hal-00542733v2⟩