Lawson criterion
noun Physics.
(in a hypothetical nuclear fusion reactor) the requirement that in order for the energy produced by fusion to exceed the energy expended in causing the fusion, the product of the density of the fuel and the time during which it is confined at that density (Lawson product) must be greater than a certain number that depends on the kind of fuel used.
Origin of Lawson criterion
after John David
Lawson (born 1923), English physicist, who formulated it in 1957