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It was invented in the 1950s by Soviet physicists Igor Tamm and Andrei Sakhov, inspired by an original idea of Oleg Lavrentyev. It is one of several types of magnetic confinement devices, and is one of the most-researched candidates for producing controlled thermonuclear fusion power. Magnetic fields are used for confinement since no solid material could withstand the extremely high temperature of the plasma. An alternative is the stellarator.