Towards steady state operation in large tokamaks: The experience of TORE SUPRA superconducting magnet system

The TORE SUPRA (TS) tokamak is the first important application of superconductivity in Plasma Physics on a large scale. Overall, despite the differences in design and size, the accumulated reliable experience over 16 years of operation is a useful tool to prepare the manufacture and the operation of the ITER magnets.An overview is given about the main design choices of the superconducting toroidal field (TF) system. The acceptance tests of the systems are described with details concerning the problems encountered and solved during this phase.The actual status of the system is described through a presentation of the present operation and of the solutions to mitigate the effects of fast safety discharges.The behaviour of the TF system during long plasma discharges in TS is a good introduction to the situation in a steady state tokamak reactor. It can be observed that the long plasma discharges do not bring a significant cryogenic load.