Design of an improved vacuum vessel protection for very long pulse operation in Tore Supra

The present concept of Tore Supra vacuum vessel wall protection, by means of actively cooled stainless steel cooling panels, will be improved in order to cope with the CIEL project requirements (radiated power of at least 10 MW yielding heat flux up to 0.3 MW/m2 for up to 1000 s). Therefore, new die formed stainless steel cooling panels have been developed and their performance were compared with different design solutions. Results of 3-D thermal and thermomechanical elastic stress analysis associated with fatigue estimates of the corrugated vacuum vessel structure are presented. They take into account especially the effect of heat deposition on the vessel wall due to radiating plasma power losses through an unavoidable very small fraction of unprotected area remaining in the improved vessel covering.