Lawson criterion

A calculation made in 1955 by the British physicist John Lawson of the plasma conditions a fusion reactor must meet to produce more energy than it loses. It was classified at first and published in 1957. In its original form it is a threshold on density multiplied by energy confinement time, which depends on temperature; folding temperature in gives the triple product used throughout this benchmark. The version most quoted today is the condition for ignition, where the fusion reactions' own heating balances every loss: for deuterium-tritium fuel, a triple product of about 3 × 10²¹ keV·s·m⁻³ at an ion temperature of about 14 keV. A plasma short of that threshold can still give useful gain.

Vocabulary id

concept:lawson-criterion

Scheme

Concepts

Back to the glossary.