text: In 1950–1951 in the Soviet Union, Igor Tamm and Andrei Sakharov first discussed a tokamak-like approach. Experimental research on those designs began in 1956 at the Moscow Kurchatov Institute by a group of Soviet scientists led by Lev Artsimovich. The tokamak essentially combined a low-power pinch device with a low-power stellarator. The notion was to combine the fields in such a way that the particles orbited within the reactor a particular number of times, today known as the "safety factor". The combination of these fields dramatically improved confinement times and densities, resulting in huge improvements over existing devices.