Tokamak: the name is an acronym from the Russian "toroidal chamber, magnetic coils." It describes a type of particularly efficient fusion machine that was developed by Soviet research in the late 1960s and adopted worldwide during the following decade.
ITER will be the largest and most powerful tokamak ever built. It is an assembly of 15 major systems, one million components and some 10 million individual parts (each one identified by a unique number for assembly purposes).
The assembly of the ITER Tokamak will begin in 2015 as the first components are delivered to the ITER site. The delicate process of installing and aligning parts weighing up to 1,250 tons, within absolutely minimal tolerances, will last about five years.