Fusion: Princeton plasma powers ahead

Researchers in the US set a new record for thermonuclear fusion power output last month when they introduced tritium into a high-temperature deuterium plasma in the Tokamak Fusion Test Reactor (TFTR) at the Princeton Plasma Physics Laboratory. TFTR achieved 6.1 MW of fusion power, with significant fusion activity in the plasma lasting for 0.7 s, from a plasma containing equal amounts of deuterium and tritium. However, the output power was less than one-quarter of the 29.4 MW needed to maintain the plasma. The previous record was 1.7 MW of power for 2 s, in a plasma containing 11% tritium, at the Joint European Torus (JET) at Culham in the UK (Physics World December 1991 p5). JET required 14.3 MW of input power.