Tokamak

The Tokamak is a type of magnetic confinement device, and is one of the most-researched candidates for producing controlled thermonuclear fusion power. Magnetic fields are used for the confinement of plasma, since no solid material could withstand the extremely high temperatures involved. Tokamaks were invented in the 1950s by Soviet physicists.

Steam rises gently from the Tokamak. You can interact with the it, but nothing appears to happen.