A Deuterium fusion reactor is a type of a nuclear fusion reactor used as a power source on UNSC warships.
Based on the name, a deuterium fusion reactor probably combines deuterium nuclei (a light hydrogen isotope) into heavier elements, accompanied by a net gain of energy. Deuterium may be fused with itself, or with tritium, another hydrogen isotope. The latter reaction is the easiest to initiate.
- Halo: Reach (First appearance)