# Fusion reactors

Experimental machines that join light atoms, as the Sun does.

Source page: https://www.materialinsights.org/energy/e_fusion/

Capture · Emerging · No. 47

- Capture
- Output: Heat (experimental)
 Capture · Emerging · Foundation · Energy

NIF's record laser shot in 2025 released 8.6 MJ of fusion energy, but its lasers drew about 300 MJ from the grid.

Chart: Illustration: Fusion reactors

##### Where it comes from

Chart: Map of where it comes from

Fusion joins light atoms, as the Sun does. Tokamaks and stellarators hold plasma above 100 million °C in magnetic fields; lasers crush pea-sized fuel capsules instead.

##### Three things to know

1. JET held a plasma gain of 0.33 for five seconds in 2021; ITER aims for a gain of 10 in 400-second pulses.
2. ITER needs 100,000 km of niobium-tin superconducting strand, over 400 tonnes, to make its confining magnetic fields.
3. Most activated materials in a fusion plant should be recyclable after about 100 years, but waste volumes are expected to be large.

##### The journey

1. 1 **Light atoms**Deuterium, plus tritium bred from lithium
2. 2 **Confinement**Magnets hold plasma, or lasers crush fuel
3. 3 **Fusion**Nuclei join above 100 million °C
4. 4 **Blanket**Neutrons deposit heat and breed tritium
5. 5 **Turbine**Heat to electricity, 35-38% assumed

##### Go deeper pick a tab to open it in full

## Other sections

- [Overview](https://www.materialinsights.org/energy/e_fusion/overview/index.md)
- [Correlation](https://www.materialinsights.org/energy/e_fusion/correlation/index.md)
- [Efficiency](https://www.materialinsights.org/energy/e_fusion/efficiency/index.md)
- [Techniques](https://www.materialinsights.org/energy/e_fusion/techniques/index.md)
- [Resources and labour](https://www.materialinsights.org/energy/e_fusion/resources/index.md)
- [Impact on the biosphere](https://www.materialinsights.org/energy/e_fusion/biosphere/index.md)
- [Relationships](https://www.materialinsights.org/energy/e_fusion/links/index.md)