The arc reactor is some kind of fusion reactor that has the ability to generate an electromagnetic field, provide clean energy, and blow things up. In the comics, Tony Stark uses it for various purposes, primarily to recharge his armor and other electronic devices. Fusion reactors that could provide a limitless source of energy could be a reality in less than a decade. This is according to scientists at the Massachusetts Institute of Technology who claim to have come up with a commercially viable fusion reactor design. Named ARC, the planned reactor will be a tokamak - or donut-shaped – system and would generate the same amount of energy as much larger designs - much like the reactor used by Tony Stark in the hit movie Iron man