Tokamak Learning Lab

Fusion Power Generator

Drive a magnetic-confinement reactor toward ignition and watch the physics respond.

Reactor state Startup Net electric 0 MW Energy gain Q 0.0

Mission Control

Challenges

0 of 7 complete

Where you are

Lawson Operating-Point Map

Confinement parameter nτE vs. temperature. Cross the upper curve and alpha self-heating sustains the burn: ignition.

Ignition curve Breakeven (Q = 1) Your operating point Real machines

Real devices placed for scale (illustrative). None has yet crossed the ignition curve by magnetic confinement; NIF reached ignition with lasers.

Energy budget

Power Balance

External heating in vs. fusion power out. Q is the ratio. Of the fusion energy, alphas (20%) stay to heat the plasma; neutrons (80%) deposit in the blanket.

External heating in
0 MW
Fusion power out
0 MW
Heating input α self-heating (stays) Neutrons → blanket
Gain factor Q = 0.0

History

Output Over Time

Net electrical output (teal) and fusion power (amber) over the last ~40 seconds of simulated time.

Peak net electric 0 MW

Why so hot?

D-T Reactivity

How fast deuterium and tritium fuse as the plasma heats up. The rate climbs steeply, peaks near 65 keV, then eases, but reactors run cooler (~10-20 keV) because confinement there is achievable.

Reaction rate ⟨σv⟩ Your temperature

Follow the energy

Energy Flow

Where the power goes: heating and fusion in, through the blanket and turbine to gross electricity, minus the plant's own draw, leaving the net that reaches the grid.

The reaction

D-T Fuel Cycle

Deuterium and tritium fuse into helium and a fast neutron; the neutron breeds fresh tritium from lithium in the blanket, closing the fuel loop.

Plasma core

A hot charged gas does the work.

Heat deuterium and tritium until their nuclei move fast enough to fuse. The goal is a dense, stable plasma that releases more heat than the injectors consume.

Go deeper

Select a component on the reactor to see the physics behind it.

Raise temperature and confinement together to move toward ignition.

Reference

Glossary

Triple product (nTτE)
Density times temperature times energy confinement time, the single figure of merit for fusion progress. D-T ignition needs about 3×10²¹ keV·s·m⁻³.
Lawson criterion
The threshold where fusion self-heating balances energy losses. Above it, the plasma can sustain itself without external heating.
Energy gain (Q)
Fusion power produced ÷ external heating power supplied. Q = 1 is scientific breakeven; Q → ∞ is ignition.
Confinement time (τE)
How long the plasma holds its energy before it leaks out. Stronger magnetic fields and larger devices increase it.
Alpha heating
Each D-T reaction makes a 3.5 MeV helium nucleus (alpha, ~20% of the energy) that stays in the plasma and heats it. The 14.1 MeV neutron (~80%) escapes.
Tritium breeding ratio
Tritium bred in the lithium blanket per tritium burned. Above 1.0 the plant replaces its own fuel.
Divertor
The component that exhausts helium ash and heat from the plasma edge, protecting the vessel wall.
Disruption
A sudden loss of confinement when plasma pressure outruns the magnetic field, dumping energy onto the walls.

The motivation

Why fusion?

Fuel from seawater

Deuterium comes from ordinary water and tritium is bred from lithium, so the fuel is effectively limitless.

Enormous energy density

A few grams of deuterium-tritium fuel release the energy of tons of coal.

No meltdown

The reaction stops the instant conditions slip, so a runaway meltdown is not possible.

No long-lived waste stream

It makes no high-level, long-lived radioactive waste the way fission does.

Predict, then test

Make a prediction

Loading a question...