Impurity transport and its modification by MHD in tokamak plasmas, with application to Tungsten in the WEST tokamak

P. Maget (1) , J Frank (2) , O. Agullo (2) , X. Garbet (1) , H. Lütjens (3)

1 IRFM - Institut de Recherche sur la Fusion par confinement Magnétique
2 PIIM - Physique des interactions ioniques et moléculaires
3 CPHT - Centre de Physique Théorique [Palaiseau]

The neoclassical transport of impurities is investigated analytically and numerically in this work, and the effect of a magnetic island for a WEST plasma is described. It is shown that the poloidal asymmetry of the impurity density can be described with a simple analytical model, and numerical simulations with a non linear fluid code confirm the analytical findings. The poloidal asymmetry tends naturally to cancel as the impurity profile evolves towards its steady state. When a magnetic island is present, temperature screening is lost locally above a critical island size. Tungsten transport is however dominated by turbulence on WEST. Simulations with a turbulent transport model confirm that the Tungsten profile is flat, as observed, but that the poloidal asymmetry remains close to its neoclassical value.

Domaines: Physique [physics]; Physique des plasmas [physics.plasm-ph]

P. Maget, J Frank, O. Agullo, X. Garbet, H. Lütjens. Impurity transport and its modification by MHD in tokamak plasmas, with application to Tungsten in the WEST tokamak. 46th European Physical Society Conference on Plasma Physics (EPS 2019), Jul 2019, Milan, Italy. ⟨cea-02555120⟩