World Record Plasma Discharge in Tore Supra

On July 30th 2002, the engineers and scientists of the Association Euratom-CEA in Cadarache (France) have achieved a three and a half minutes long plasma discharge on Tore Supra, sustained by 3MW of current drive power, thus requiring to exhaust more than 600 Megajoules of thermal energy during the experiment. It establishes a new world record in this domain after the 280MJ discharges of 1996. Prior to the record discharge, a number of long pulse shots have been achieved, demonstrating the capability of Tore Supra to run long pulses on a regular basis.

Tore Supra started operations in 1988 and is one of the largest tokamaks operating today. It was the first one which used a series of superconducting toroidal coils to generate a strong permanent toroidal magnetic field. A new configuration of the actively cooled plasma facing components has been implemented this year.

Fusion is an option for large scale energy supply with intrinsic safety and environmental benefits in the long term.

The capability to run long pulse plasmas on a regular basis opens the way to explore new scientific questions in ITER-relevant conditions. These investigations involve the aging of the toroidal limiter under thermal cycling, limiter erosion, hydrogen wall trapping, real time discharge control and performance optimisation (confinement and stability) through a set of feedback control systems.

ITER is an international fusion energy research and development project with the goal of taking the next major step in the development of fusion energy as a safe and sustainable energy source for our planet.
Cadarache, together with Vandellos (Spain), is the site proposed by the European Union to host the ITER machine.

The remarkable result of Tore Supra has been obtained with the newly completed configuration of actively cooled plasma facing components which ensures that every square centimetre of the wall in front of the plasma is actively cooled. It is worth recalling that two years were needed for the European industry to complete the complex manufacturing of the 600 fingers which constitute the toroidal limiter of the project, each of them being composed of 21 tiles made of carbon fibre composite bonded to the copper base. One and a half year was necessary to install the overall assembly, including the 5m in diameter limiter ring with a position accuracy of 1/10th of a millimetre to ensure an homogeneous distribution of the heat deposition.

This record value, very quickly achieved during the experimental campaign, is in no case a limit in performance. The range of accessible parameters has now to be explored in order to establish its actual capability.