Leaderboards

Fusion triple product (nTτ_E)

Density × ion temperature × energy confinement time. The fairest single comparator across confinement approaches.

Ranked in 10²¹·m⁻³·keV·s. 2 targets excluded.

Ion temperature

Record with qualifier peak or sustained — they are different achievements and conflating them is a listed red flag.

Ranked in keV. 2 targets excluded.

Energy confinement time (τ_E)

How long the plasma retains its energy (τ_E) — stored energy divided by heating power. NOT the length of the discharge: a machine can hold a plasma for 1,000 seconds with a confinement time of a fraction of a second, and conflating the two is one of the most common errors in coverage.

Ranked in s. 2 targets excluded.

Plasma duration

Wall-clock length of a sustained discharge. Distinct from confinement time, and routinely confused with it in press coverage.

Ranked in s. 39 design parameters excluded. 5 targets excluded.

Why some metrics have no leaderboard

• Plasma density — no better direction — a larger machine is not a better one
• Major radius — no better direction — a larger machine is not a better one
• Minor radius — no better direction — a larger machine is not a better one
• Laser energy on target — no better direction — a larger machine is not a better one
• Triple product — one measurement held. Fewer than 3 entries is a list, not a ranking. See coverage.

Values are converted to each metric's canonical unit before sorting, and the figure as published is shown beside it. Ion temperature is held in kelvin for some devices and keV for others; ranking the raw numbers puts a 100 million degree plasma below a 40 million degree one. Where no conversion is known, the measurement is excluded rather than ranked on a number that means something else.