Impurity radiation modulations in an ergodic divertor

The 3-D geometry of radiation losses is investigated in the Tore Supra ergo dic divertor, Measurements from passive bolometers located on the divertor coils show evidence of toroidal and poloidal radiation modulations. They we re interpreted using a 3-D code solving heat transport equation that gives the whole geometry of plasma radiation in a divertor configuration close to Ton Supra. The results of the code are in qualitative agreement with the m easurements and they show that the total radiated power is underestimated w hen inferred from standard bolometers located between divertor modules. Max imum of radiation in front of the modules is explained by the multiplicatio n of radiative zones at this place due to the intersection of field lines w ith the vessel wall. This effect leads to non-monotonic temperature profile s along field lines in the boundary plasma. (C) 2001 Elsevier Science B.V. All rights reserved.