Helium fusion

Helium fusion is a kind of nuclear fusion, with the nuclei involved being helium.

Additional recommended knowledge

Weighing the right way

Recognize and detect the effects of electrostatic charges on your balance

Better weighing performance in 6 easy steps

The fusion of helium-4 nuclei (alpha particles) is known as the triple-alpha process, because fusion of just two helium nuclei only produces beryllium-8, which is unstable and breaks back down to two helium nuclei with a half life of 1×10^-16 to 2.6×10^-16 seconds. If the core temperature of a star exceeds 100 million kelvins (100 megakelvins), as may happen in the later phase of red giants and red supergiants, then a third helium nucleus has a significant chance of fusing with the beryllium-8 nucleus before it breaks down, thus forming carbon-12. Depending upon the temperature and density, an additional helium nucleus may fuse with carbon-12 to form oxygen-16, and at very high temperatures, additional fusions of helium to oxygen and heavier nuclei may occur (see alpha process).

The fusion of helium-3 with itself or with helium-4 occurs during the fusion of hydrogen in main sequence stars (see proton-proton chain), and is not ordinarily referred to as helium fusion.

See also

• Fusion power
• Cold fusion

References

Alak K. Ray (2004) Stars as thermonuclear reactors: their fuels and ashes (arxiv.org article)