TEMPERATURE PROFILES IN STOCHASTIC BOUNDARIES

During ergodic divertor operation, strong poloidal and radial modulati ons of the temperature field have been observed in stochastic boundari es. Using field line tracing, one finds that steady state modulations are governed by field lines stochasticity. A 1D radial model is propos ed, based on a superimposition of two coupled diffusive networks, a fi rst one standing for the transverse diffusion and a second one account ing for the effects of the stochastic parallel transport. Modulations are then recovered under some conditions. The model predicts that the temperature in the core plasma is not affected by the divertor, which is experimentally verified.