In a fission reactor, I know the energy goes into the water, which creates steam and that turns a turbine. But it looks like fusion reactors use a near vacuum and high powered magnets. Once two atoms actually fuse, where does that energy "go"? Does the new helium atom just bounce around the containment unit? How do we actually extract meaningful energy from such a closed system?
Edit: https://en.wikipedia.org/wiki/ITER for visuals.