JET-R(99)02

Poloidal Density Variation of Impurities in a Rotating Tokamak Plasma ­ Flux Surface Coordinates and Effect on Transport Coefficients

The poloidal variation of impurity densities over magnetic surfaces brings about an enhancement of neoclasical transport coefficients, as shown by Romanelli and Ottaviani for impurities in the Pfirsch Schlüter regime and by Helander for particles in the banana-plateau regime, both in a large aspect ratio tokamak. The same effect will occur in a finite aspect ratio tokamak and therefore it is considered to be relevant for inclusion in transport codes [6] for comparison with the experimental measurements of impurity transport. Here an expression for the impurity-density poloidal-variation generated by the fast toroidal rotation of the plasma column is presented in general coordinates.
Name Size  
JETR99002 60.43 Kb