Equations · equation
Lawson Criterion
Plasma Physics · 1957
- Equation
- n·T·τ_E ≥ 3×10²¹ keV·s/m³
- Field
- Plasma Physics
- Named After
- John D. Lawson
- Year
- 1957
Symbols
n fuel density · T temperature · τ_E energy confinement time — how long the heat stays put · the triple product a fusion plasma must exceed to yield net power
Significance
The finish line for fusion power: hold a plasma dense enough, hot enough, long enough — achieve any two and the third gets you. Tokamaks chase confinement time, laser fusion chases density. In December 2022 the National Ignition Facility crossed it far enough to get more fusion energy out of the capsule than the laser delivered to it, the first target gain above one; the facility as a whole still draws far more from the wall than the shot returns, so the race that matters is not over.
Spectral Types
G-type Stars
Referenced by
element
equation
Open on the Equations shelf — the interactive card, the filters, and everything alongside it.