Nuclear Fusion
A nuclear reaction in which two light atomic nuclei collide and combine to form a single heavier nucleus, releasing vast amounts of energy.
Governing formula
²₁H + ³₁H → ⁴₂He + ¹₀n + 17.6 MeV
SI unit
MeV (Mega-electronvolts)
In depth
Fusion requires overcoming the repulsive electrostatic Coulomb barrier between positively charged nuclei, requiring extreme temperatures (> 10⁸ K) and high plasma pressures. Fusion yields greater energy per unit mass than fission and produces no high-level long-lived radioactive waste.
Examples in the real world
Thermonuclear proton-proton chain reactions powering the Sun, and experimental Tokamak reactors (like ITER) attempting magnetic confinement fusion.