Kärnklyvningen

Kärnklyvningen, also known as nuclear fission, is a nuclear reaction process where the nucleus of an atom splits into two or more smaller, lighter nuclei. This process is typically initiated by the absorption of a neutron. When a heavy, unstable nucleus like uranium-235 or plutonium-239 absorbs a neutron, it becomes even more unstable and undergoes fission. The fission event releases a significant amount of energy in the form of kinetic energy of the fission fragments and gamma radiation.

Crucially, the fission process also releases additional neutrons. These neutrons can then go on to induce fission in other nearby fissile nuclei, leading to a self-sustaining chain reaction. This chain reaction is the fundamental principle behind nuclear power reactors and nuclear weapons. In a nuclear reactor, the chain reaction is carefully controlled using control rods to absorb excess neutrons, regulating the rate of fission and the power output. In a nuclear weapon, the chain reaction is designed to proceed as rapidly as possible, releasing a massive amount of energy in a very short time.

The products of nuclear fission include not only the smaller nuclei but also various radioactive isotopes, which are a significant consideration for waste disposal and safety in nuclear applications. The energy released during fission is a direct consequence of the difference in binding energy between the original heavy nucleus and the resulting fission fragments.