ITER is an international tokamak (magnetic confinement fusion) research/engineering proposal which is intended to be an experimental project between today's studies of plasma physics and future electricity-producing fusion power plants. It will build upon research conducted with devices such as DIII-D, EAST, TFTR, JET, JT-60, and T-15, and will be considerably larger than any of them.

On November 21, 2006, the seven participants formally agreed to fund the project. The program is anticipated to last for 30 years - 10 years for construction, and 20 years of operation - and cost approximately 10 billion Euros, which would make it one of the most expensive modern technoscientific megaprojects. It will be based in Cadarache, France. It is technically ready to start construction and the first plasma operation is expected in 2016.

ITER will be designed to produce approximately 500 MW (500,000,000 watts) of fusion power sustained for up to 400 seconds (compared to JET's peak of 16 MW for less than a second) by the fusion of about 0.5 g of deuterium/tritium mixture in its approximately 840 c.m. reactor chamber. Although ITER is expected to produce net power in the form of heat, the generated heat will not be used to generate any electricity.

According to the ITER consortium, fusion power offers the potential of environmentally benign, widely applicable and essentially inexhaustible electricity, properties that they believe will be needed as world energy demands increase while simultaneously greenhouse gas emissions must be reduced, justifying the expensive research project. However, others have criticised the ITER proposal, saying that nuclear fusion has all the problems of nuclear power, including the production of nuclear waste and the risks of a nuclear accident.

ITER was originally an acronym for International Thermonuclear Experimental Reactor, but that title was dropped due to the negative popular connotation of "thermonuclear," especially when in conjunction with "experimental". "Iter" also means "trail" or "path" in Latin, and this double meaning reflects ITER's role in harnessing nuclear fusion as a peaceful power source.

Main Objectives

The official objective of ITER is to "demonstrate the scientific and technological feasibility of fusion energy for peaceful purposes". ITER has a number of specific objectives, all concerned with developing a viable fusion power reactor:

  • To momentarily produce ten times more thermal energy from fusion heating than is supplied by auxiliary heating (a Q value of 10).
  • To produce a steady-state plasma with a Q value greater than 5.
  • To maintain a fusion pulse for up to eight minutes.
  • To ignite a 'burning' (self-sustaining) plasma.
  • To develop technologies and processes needed for a fusion power plant - including superconducting magnets and remote handling (maintenance by robot).
  • To verify tritium breeding concepts.
  • To refine neutron shield/heat conversion technology (most of energy in the D+T fusion reaction is released in form of fast neutrons).

More information on ITER can be found on the official ITER Web-site.