First plasma at Princeton's Tokamak Fusion Test Reactor

The first of a new generation of large tokamaks was completed just in time for Christmas. Princeton's Tokamak Fusion Test Reactor achieved its first test plasma in the early hours of 24 December. TFTR is one of four new tokamaks large enough to achieve plasma conditions that are expected to suffice for the demonstration of “scientific breakeven”—the output of fusion power equal to the input of heating power from external sources.