MIT tokamak Alcator C exceeds Lawson criterion

In 1957 John Lawson at Harwell pointed out a crucial minimum requirement for the achievement of net power output from a deuterium–tritium plasma in any fusion device. No matter what the temperature, Lawson showed, a thermalized D–T plasma cannot put out more fusion power than the input power required to keep it hot unless $nτ,$ the product of the ion density and the energy confinement time (often refered to as the confinement parameter or Lawson parameter), exceeds $6×1013 sec cm−3.$