Nuclear fusion is a process in which small atomic nuclei fuse and release energy. In a hydrogen bomb, fusion of deuterium and tritium (two isotopes of hydrogen) releases four times as much energy as the same mass of uranium in a fission bomb.
To derive useful power from nuclear fusion, the nuclei need to be confined at pressures and temperatures far higher than any material can withstand. There are two ways to do this - either with magnetic fields, which force the charged particles to circle around rather that escape, or with "inertial confinement" like in a bomb, but driven by lasers on a much smaller scale.
Both fission and fusion produce small amounts of nuclear waste. The advantages of fusion are that it does not have the anti-nuclear stigma of fission, and the reactors will be so expensive as to not threaten an end to the fossil fuel industry.
- On a mass basis, the D-T fusion reaction releases over four times as much energy as uranium fission.Nuclear Fusion Power World Nuclear Association, 2022.
- Recently there has been some excitement about a hybrid technique, using inertia from massive pistons compressing a magnetic field, which keeps the hot plasma away from the reactor walls.Helion Energy