The Department of Energy sponsors a laboratory that is currently working on magnetic fusion devices based on what principle?
National Spherical Torus Experiment The National Spherical Torus Experiment (NSTX) is an innovative magnetic fusion device based on the "spherical tokamak" concept. It was constructed by the Princeton Plasma Physics Laboratory (PPPL) in collaboration with the Oak Ridge National Laboratory, Columbia University, and the University of Washington at Seattle.
Fusion ignition Fusion ignition is the point at which a nuclear fusion reaction becomes self-sustaining. This occurs when the energy being given off by the fusion reactions heats the fuel mass more rapidly than various loss mechanisms cool it. At this point, the external energy needed to heat the fuel to fusion temperatures is no longer needed. As the rate of fusion varies with temperature, the point of ignition for any given machine is typically expressed as a temperature.