ITER

ITER << IH tuhr >> is an experiment designed to demonstrate the potential of nuclear fusion as a source of electrical power. Nuclear fusion involves combining the nuclei (cores) of atoms (see Fusion). Fusion releases tremendous amounts of energy and carries a relatively small risk of environmental pollution. ITER is a joint project of China, the European Union, India, Japan, Russia, South Korea, and the United States. The fusion device, called a reactor, will be constructed in Cadarache, France, near Marseille. The name ITER was originally conceived to stand for International Thermonuclear Experimental Reactor, but that name is no longer used. The word iter means the way in Latin.

The ITER reactor will consist of a tokamak, a doughnut-shaped chamber in which fusion takes place. A tokamak uses powerful magnets to confine a fuel, which will then be heated, causing fusion. ITER’s fuel consists of deuterium and tritium—two isotopes (forms) of hydrogen—which fuse to produce helium nuclei, giving off particles called neutrons. The neutrons, which move at high speeds, heat the materials surrounding the reactor. This heat could be used to run a turbine, generating electric power.

ITER was designed to show that a fusion reactor can produce more power than it uses. It will be able to produce about 500 megawatts (million watts) of fusion power using 50 megawatts of input power. ITER was also designed to help test and develop the magnets and other reactor parts needed for future fusion power plants.

Researchers worked on the design and engineering of ITER from the late 1980’s to the early 2000’s. In 2005, the ITER partners chose Cadarache as the facility’s construction site. Operation of the reactor is planned to begin in the late 2020’s and to last about 20 years. Researchers hope that knowledge gained from ITER will enable construction of the first fusion power plant.

See also Nuclear energy (Experimental fusion devices).