A sourced, cited encyclopedia of fusion energy. Every entry independently sourced, every claim traceable. No ads, no sponsors — subscriber-funded.
26 entries · Concepts & Physics · Last updated 9 Aug 2026
Nuclear FusionReviewed
The process that powers the stars — and the engineering quest to harness it on Earth.
PlasmaReviewed
The fourth state of matter and the medium in which fusion reactions take place.
Coulomb BarrierReviewed
The electrostatic wall between two nuclei that must be overcome for fusion to occur.
Fusion Cross-SectionReviewed
The probability that two nuclei will fuse at a given energy — the curve that dictates which fuels are practical.
Lawson CriterionReviewed
The condition a fusion plasma must meet before a reactor can produce more energy than it consumes.
Fusion Triple ProductReviewed
The single number — density × temperature × confinement time — that measures how close a plasma is to net energy.
Energy Confinement TimeReviewed
How long a plasma holds its heat — and why losing it too fast kills a fusion reactor.
Plasma BetaReviewed
The ratio of plasma pressure to magnetic pressure — a key measure of how efficiently a device uses its magnets.
IgnitionReviewed
The point where a fusion plasma sustains itself without external heating — the ultimate milestone.
Fusion Energy Gain Factor (Q)Reviewed
The ratio of fusion power out to heating power in — the scoreboard of every fusion experiment.
Break-EvenReviewed
When a fusion device produces as much energy as it consumes — and why the definition matters.
BremsstrahlungReviewed
The radiation a plasma emits when electrons brake near ions — a major energy-loss channel in fusion reactors.
Plasma InstabilitiesReviewed
The ways a confined plasma can shake itself apart — the central challenge of every fusion design.
Deuterium–Tritium FuelReviewed
The easiest fusion fuel to ignite, and the one most reactor designs are built around.
Tritium Breeding RatioReviewed
Whether a fusion reactor can manufacture its own tritium fuel faster than it burns it.
Aneutronic FusionReviewed
Fusion reactions that release almost no neutrons — cleaner in principle, far harder in practice.
Proton–Boron FusionReviewed
An aneutronic reaction that could eliminate radioactive waste — if the physics can be made to work.
Magnetic Confinement FusionReviewed
Using powerful magnetic fields to hold a fusion plasma in place long enough to produce energy.
Inertial Confinement FusionReviewed
Compressing fuel pellets with lasers or particle beams to trigger fusion in billionths of a second.
TokamakReviewed
The doughnut-shaped magnetic cage that has come closest to sustained fusion energy.
StellaratorReviewed
A twisted magnetic-confinement device that trades simplicity for inherent steady-state operation.
Magnetic MirrorReviewed
An open-ended magnetic trap that confines plasma by reflecting particles from regions of stronger field.
Field-Reversed ConfigurationReviewed
A compact, self-organized plasma ring with no external toroidal field — simple hardware, complex physics.
Z-PinchReviewed
Compressing a plasma column with its own magnetic field — one of the oldest and simplest fusion concepts.