Nuclear fusion

Nuclear fusion is a reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles (neutrons or protons). The difference in mass between the reactants and products is manifested as either the release or absorption of energy. This difference in mass arises due to the difference in atomic "binding energy" between the atomic nuclei before and after the reaction. Fusion is the natural engine that powers stars.

Spaceships, large oceanic vehicles and large energy-hungry cities use various types of fusion reactors. Plasma is preferred over antimatter as it is safer, and is confined by a magnetic field. Fusion is widely used as a power source in Type I and beyond.

In comparison, nuclear fission releases far less energy.