Physicists have presented a design for a smaller fusion reactor.
The International Thermonuclear Experimental Reactor (ITER) has been in limbo since 1998, when the funding governments refused to provide the required r7 billion. The fall in funding came about because support for fusion from the USA had declined, and Russia had little money to make available. The USA pulled out of the project in 1999, and the remaining fusion researchers redesigned the reactor, halving the original capital cost.
The operating principle behind the new design remains the same. However, many of the key parameters have been reduced (see table).
The reactor is no longer designed to ignite the plasma. Ignition occurs when the alpha particles provide enough energy to sustain the reaction and no further heat input is required. The new design is for 67% of the plasma's energy to be provided by alpha particles. Despite the need to input energy, the reduced ITER should produce ten times as much energy as it consumes.
It has yet to be decided where the ITER will be built. Possible sites include Cadarache in France and three locations in Japan. Canada has proposed building the reactor at Clarington, near Toronto. Canada suggests that this would be a good site, as tritium is already produced here, that it would provide a compromise between Europe and Japan, and that it might encourage the USA to rejoin the project.
