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What happens when deuterium and tritium nuclei fuse?
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nuclear fusion
Interior of the U.S. Department of Energy's National Ignition Facility (NIF), located at Lawrence Livermore National Laboratory, Livermore, California. The NIF target chamber uses a high-energy laser to heat fusion fuel to temperatures sufficient for thermonuclear ignition. The facility is used for basic science, fusion energy research, and nuclear weapons testing.
When deuterium and tritium nuclei fuse, they undergo a reaction that releases a significant amount of energy, totaling approximately 17.58 MeV. This process is the most practical fusion reaction for controlled power generation because it requires only moderate plasma temperatures to achieve a net energy release.1
During the reaction, the two hydrogen isotopes combine to produce two primary particles:2
- An alpha particle: A helium nucleus carrying 3.5 MeV of energy. Because it is electrically charged, it remains confined within the plasma, transferring its energy to other nuclei to help sustain the reaction.2
- A neutron: A particle carrying 14.1 MeV of energy. Being electrically neutral, the neutron is unaffected by magnetic fields and escapes the plasma. In a reactor, this neutron is typically captured by a surrounding lithium blanket, where its energy is converted into heat for electricity generation.2
This reaction is highly efficient and serves as a promising, effectively inexhaustible source of energy, as the necessary fuel—deuterium—can be extracted from seawater, and tritium can be bred using the neutrons produced during the fusion process.2