In a nuclear reactor one wishes to keep K slightly above 1. Return to top 14.c. Fusion Due to surface effects light nuclei, with the notable exception of 4 He, usually have much smaller binding energies per nucleon then heavier ones. This implies that if they fuse together they go into a lower energy state and kinetic energy is produced. That is the basis of fusion reastions.
Fusion reactions produce the energy radiation of stars, among others of the sun.
Starting mostly from H heavier atoms are fused together to create more stable nuclei, mostly He. The ceration of He nuclei happens in a series of nuclear reaction which, obviously, should contain beta-decays to transform some of the protons into neutrons that are required in He and other heavier atoms. In other words, the production of every a -particle releases 24 MeV kinetic energy. This is the energy that produces the heat of the sun, the energy of H-bombs and of future fusion reactors. In future fusion reactors a more promising series of nuclear reactions would start from deuterium, heavy hydrdogen that can be found in sea water in abundance.