CEA - Centre d'études de Cadarache
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Recherches et Projets

Nuclear Fusion

The aim of nuclear fusion is to produce the energy of the stars on earth.

When matter reaches very high temperatures and densities, as in the centre of the sun, hydrogen atoms fuse and release great amounts of energy. This is the reaction that scientific researchers are attempting to reproduce on earth.

To accomplish this, temperatures at about 100 million degrees must be reached and maintained while isolating the matter in an ionised gas state (plasma) from the walls of the machine through the use of powerful magnets: this is the configuration of the tokamak.

Research on fusion at Cadarache is currently being carried out in the TORE SUPRA facility, a supraconductor magnet tokamak. Beginning in 2016, further research will also be carried out in the international ITER reactor.

Since 1988, the date of its commissioning, the TORE SUPRA research facility is the largest supraconductor magnet tokamak in the world. It is supervised by the European association of EURATOM/CEA

In this machine, confinement of the plasma is obtained through the superimposition of two magnetic fields that act as invisible rails guiding the particles. The constant, uninterrupted functioning of its magnet, associated with actively cooled components confers the capacity of TORE SUPRA to produce high performance plasma over long periods of time.

To achieve these scientific objectives, TORE SUPRA has a means of heating the plasma using microwaves for a total available power on the order of 15 MWth*.

The internal wall of the tokamak is permanently cooled by a high-pressurised water circuit.

In addition to this, a specific device called the circular limiter, enables researchers to evacuate most of the power released by the plasma; this is what allowed TORE SUPRA to obtain a record plasma in 2003 with a pulse of more than six minutes during which time, energy on the order of 300 kWh was injected and extracted.

Teams from Cadarache have also been involved in programmes led by the JET tokamak project in the United Kingdom, which in 1997 succeeded in establishing a world record of 16 MW.

* MWth (thermal Mega Watt) unit measurement of thermal power (heat) MWe (electric Mega Watt) unit measurement of electrical power

With ITER, Cadarache prepares to welcome one of the most important research projects of the 21st century

In choosing to build ITER on the site of the Cadarache Research Centre, the partners of the ITER project will benefit from an exceptional environment of researchers and remarkable technological and scientific expertise. ITER, constituting a key stage in the history of fusion research, will be the first research facility in the world to integrate technological developments perfected in Europe with the TORE SUPRA facility at Cadarache, at the JET facility in England and in the rest of the world with the JT-60 in Japan and the TFTR in the United States.

The goal of ITER is to demonstrate the feasibility of fusion as a potential source of energy. Once this final stage of research has been completed, it will be up to the DEMO demonstrator to produce electricity in 2040. Very high temperatures must be reached in ITER in order to create fusion reactions that resemble those existing in the centre of the sun. These temperatures allow deuterium and tritium atoms (hydrogen isotopes), introduced in a gaseous state in the core of the research reactor, to fuse. With ITER, the main objective is to obtain fusion reactions ten times greater (500 MW) than those obtained up to the present time (50 MW). Equipment in ITER must also be tested for future industrial fusion reactors.

ITER is one of the most important international collaborations in the world. The project combines the efforts of China, the United States, Europe, the Russian Federation, India, Japan and the Republic of South Korea – more than half of the world’s population.


Overall view of TORE SUPRA
Toroïdal chamber of the
TORE SUPRA in which the
plasma circulates during tests
Airial view
Toroïdal chamber's model
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