  The turbulence-induced quasi-linear particle flux of a highly-charged,
collisional impurity species is calculated from the electrostatic gyrokinetic
equation including collisions with the bulk ions and the impurities themselves.
The equation is solved by an expansion in powers of the impurity charge number
$Z$. In this formalism, the collision operator only affects the impurity flux
through the dynamics of the impurities in the direction parallel to the
magnetic field. At reactor-relevant collisionality, the parallel dynamics is
dominated by the parallel electric field, and collisions have a minor effect on
the turbulent particle flux of highly-charged, collisional impurities.

Plasma Physics