Magnetic field stochastization at the plasma edge in Tore-Supra with t
he ergodic divertor (ED) results in a significant reduction of the imp
urity concentration and a simultaneous increase of the edge radiation.
This behavior is modelled by the codes RITM and CNET by taking the en
hancement of the energy and particle transport with ED into account. A
qualitative explanation of the influence of stochastization on differ
ent charge states of impurities is proposed.