Magnetic fusion : Tore Supra

The "plasma facing components" receive the heat from the plasma and act as thermal shields and regulate the flow of exhaust gas. The first version of these components destined to extract heat enabled the evacuation of around 3 MW in more or less stable regime on Tore Supra. The experience acquired led to the design of a new generation of limiters capable of withstanding fluxes of up to 10 MW/m2 (compared to 70 MW/m2 on the surface of the sun). These very efficient new components (CIEL project for Internal Components and Limiter ‘Composants Internes Et Limiteur’) were developed by European industries and were installed on Tore Supra in 2000. This mainly involved :

a wide surface 7m2"limiter" ring, made up of 576 horizontal fingers, capable of extracting 15 megawatts of power transferred by the plasma particles ,
a reinforced protection of the cryostat, containing the superconducting magnet system, from plasma radiation (capable of extracting 10 megawatts).

All these components have the possibility of evacuating a total of 25 megawatts of power injected over period up to 1000 seconds.

5 - Power injection (heating)

In Tore Supra, several techniques of heating the plasma by radiowaves are used. Improvements on existing systems are being considered so as to initially raise the injection capacity to 12MW for1000s (CIMES-1 project standing for "Components for Injection of Matter and Stationary Energy").

Heating antenna designed to inject 4 MW at 3.7 GHz for 1000 secs

6 - The main results

Tore Supra has been in operation since 1988 and has since this time produced more than 20 000 plasma discharges. Amongst the main breakthroughs achieved by Tore Supra are :

The practically uninterrupted operation since 1988 of the Tore Supra superconducting magnet, which in itself is a great technological success and a considerable breakthrough for the controlled fusion programme and other industries.
Mastery of long-duration plasmas (a record duration plasma of 6 minutes 30s achieved - 04/12/2003).

Long discharges in Tore Supra

Expertise in the field of technology and heating by radiowaves.
The implementation of technologies in the construction first wall components capable of withstanding heat flows of several MW/m².
Expertise in the field of plasma physics (comprehension and control of plasma edge, control of plasma heat loss, ...).