A stellarator's a device used to confine a hot plasma with magnetic fields in order to sustain a controlled nuclear fusion reaction.The magnetic field necessary to confine the plasma's generated completely by external coils. It was invented by Lyman Spitzer and the first devices were built at the Princeton Plasma Physics Laboratory in 1951. The name was given to this early fusion concept because of the possibility of harnessing the power source of the sun (which's a stellar object). Some importa… (More on Stellarator)