The objective of nuclear fusion research is to find out whether or not the nuclear energy of thelight elements, especially that released when hydrogen isotopes react to form helium, can be putto practical use to provide a virtually limitless source of energy. This research has beenconducted on an increasing scale since 1946 when a patent was taken out by Thomson and Blackmann (1946) to produce high temperatures and D-D thermonuclear fusion reactions in a toroidal electricdischarge of about 500 kA. Nowadays the research is carried out on a scale of several hundredmillion dollars a year in each of Western Europe, the U.S.A, Japan and the Soviet Union.