Stellarator is a way of magnetic confinement. (Credit: Max Planck Institute for Plasma Physics)

Isolation of hot plasma by magnetic fields so that thermonuclear fusion can occur. Because charged particles follow magnetic field lines, magnetic fields can be used to effectively isolate the plasma from the walls of the vessel and keep it there long enough to heat it to the temperatures necessary for fusion. The principle of magnetic confinement is used by tokamaks and stellarators.