Thermonuclear fusion powers the stars and produces 10 times more energy than fission. Mastering it in Earth conditions would provide an endless source of energy, but many technological challenges have yet to be solved.

The tokamak uses a toroidal magnetic cage to isolate hot plasma from vessel walls. Thermonuclear fusion can be ignited inside after reaching suitable conditions. More than 50 tokamaks are involved in fusion research today.

The idea of a stellarator is based on the premise that plasma can be held in the reaction space by means of a special helically wound magnetic field that is generated exclusively by magnetic coils of various shapes.