The superconducting tokamak Tore Supra was built in the 1980s, when the Joint European Torus (JET) started operation, with the aim of addressing technological and scientific questions relevant to long-pulse operation, in complement to JET objectives. The past 20 years of operation have confirmed that it was essential to integrate within a single device the features of high-performance long pulses in order to progress on the technological side with the level of effort needed for integration and interface management.
Besides the 20 years of successful operation of the superconducting magnet, successive developments of the actively cooled plasma-facing components have allowed us to increase progressively the level of performance of Tore Supra. Since 2001, Tore Supra has been operated with an actively cooled toroidal pump limiter, complemented by actively cooled antenna protections and wall protection [Composants Internes et Limiteur (CIEL) project], capable of removing up to 20 to 25 MW of power. The high-performance long-pulse capability of Tore Supra culminated in 2003 with record discharge durations of 6 min driven by lower hybrid current drive (LHCD).
Although Tore Supra has a circular cross section, which departs from the favorite divertor edge configuration, it has been possible to address original physics questions that are of importance for current and future scientific choices of ITER and beyond, e.g., plasma discharges driven by LHCD or ion cyclotron resonance heating (ICRH) (no neutral beams), carbon wall environment at constant temperature, ergodic edge, pellet/supersonic gas injection, electron cyclotron resonance heating-assisted mode control or plasma breakdown, etc.
The large heat exhaust margin available with the CIEL components has made possible the current installation of a new LHCD power system with 16 upgraded 700-kW klystrons and an actively cooled passive/active lower hybrid antenna, which opens the prospects for larger-density operation and larger ICRH coupling and therefore higher-performance plasmas (higher bootstrap fraction) over discharges of the same or longer duration.
This paper briefly sketches the research reported in this special issue of Fusion Science and Technology dedicated to the Tore Supra tokamak. It briefly sketches its history, describes its mission, and outlines its physics and technology results.