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Nuclear fusion
Intermediate
Light nuclei combine releasing energy.
Light nuclei join to form heavier ones, releasing energy because binding energy per nucleon rises. It needs temperatures of 10⁷–10⁸ K to overcome Coulomb repulsion.
D + T → ⁴He + n + 17.6 MeV.
Tunnelling helps in stars.
In more detail
Nuclear fusion joins light nuclei, such as deuterium and tritium, into heavier ones, releasing energy. It requires very high temperatures to overcome electrostatic repulsion.
Real-world uses
- Fusion is the source of energy in the Sun and stars.
- Fusion reactors are under development for future clean power.
- Scientists aim to produce clean energy by fusing light nuclei, such as deuterium and tritium, in reactors.
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Frequently asked questions
Why is fusion hard to achieve?
Nuclei must be brought very close together, requiring temperatures of millions of degrees.
Why is fusion attractive?
It produces little long-lived waste and uses abundant fuels.
Why is fusion hard to achieve?
Nuclei repel each other electrically, so they must be heated to extreme temperatures and held together long enough to fuse.
Related topics in Atomic & Nuclear Physics
Chain reaction · Nuclear reactors · Nuclear weapons · Fusion in stars · Fusion reactors · Neutron discovery