Transmutation

In chemistry and nuclear physics, the term transmutation denotes the conversion of one chemical element into another one.

Transmutations take place under extreme conditions in stars like the sun (e.g. nuclear fusion) and can be observed in natural radioactive decay. In principle, they can also be controlled by man. For example in nuclear fission processes (nuclear power plants, atomic and hydrogen bomb explosions). Neutron bombardment or bombardment with charged particles may lead to transmutations, e.g. in atomic reactors. Since the 1940ies, Plutonium 239 and Uranium 233 are won from Uranium 238 and Thorium 232 industrially to build atomic bombs.

In theory transmutations might have practical appliance for the creation of gold or other precious metals, but costs and effort are too high and therefore not attractive commercially. Transmutation facilities could be used to dispose nuclear waste, but as of 2011, just small experimental facilities exist. A European research facility (MYRRHA project) is planned in Mol, Belgium and might be built by 2020. The necessary time of final storage of the remaining waste should be reduced from 500,000 years to 500.

Origin

Originally, the term was used by alchemists, who for centuries believed to be able to create gold from other elements just through normal chemical reaction or magic. Such hypotheses were discussed even in the 17th, 18th, and 19th centuries.

Use in pseudoscience

Despite the lack of evidence and disappointing experiments, and against established knowledge of chemistry, the rumour that transmutations, for exampled to provide energy, can be affected with little effort holds to this day. To distinguish such hypotheses from actually possible transmutations under extreme conditions, the term CANR (Chemically Assisted Nuclear Reactions) was introduced. An example for such considerations are speculations about alleged successful experiments with cold fusion, for instance by electrolysis. In most cases, this is put in the context of a conspiracy theory, e.g. powerful interest groups prevented or covered up such experiments. Such speculations are for example spread by supporters of U.S. citizen Lyndon LaRouche.

Hypotheses about possible biological transmutations in biology take a special role and have been discussed since the 17th century, finding sporadic supporters even today.

Versions of this article in other languages

• Deutsch: Transmutation

Literature

• Mikhail Kh. Khankhasayev: Nuclear methods for transmutation of nuclear waste - problems, perspectives, cooperative research. World Scientific Publ., 1997, ISBN 981-02-3011-7.