Nuclear transmutation is the conversion of one chemical element or an isotope into another chemical element.[1] Nuclear transmutation occurs in any process where the number of protons or neutrons in the nucleus of an atom is changed.
A transmutation can be achieved either by nuclear reactions (in which an outside particle reacts with a nucleus) or by radioactive decay, where no outside cause is needed.
Natural transmutation by stellar nucleosynthesis in the past created most of the heavier chemical elements in the known existing universe, and continues to take place to this day, creating the vast majority of the most common elements in the universe, including helium, oxygen and carbon. Most stars carry out transmutation through fusion reactions involving hydrogen and helium, while much larger stars are also capable of fusing heavier elements up to iron late in their evolution.
Elements heavier than iron, such as gold or lead, are created through elemental transmutations that can naturally occur in supernovae. One goal of alchemy, the transmutation of base substances into gold, is now known to be impossible by chemical means but possible by physical means. As stars begin to fuse heavier elements, substantially less energy is released from each fusion reaction. This continues until it reaches iron which is produced by an endothermic reaction consuming energy. No heavier element can be produced in such conditions.
One type of natural transmutation observable in the present occurs when certain radioactive elements present in nature spontaneously decay by a process that causes transmutation, such as alpha or beta decay. An example is the natural decay of potassium-40 to argon-40, which forms most of the argon in the air. Also on Earth, natural transmutations from the different mechanisms of natural nuclear reactions occur, due to cosmic ray bombardment of elements (for example, to form carbon-14), and also occasionally from natural neutron bombardment (for example, see natural nuclear fission reactor).
Artificial transmutation may occur in machinery that has enough energy to cause changes in the nuclear structure of the elements. Such machines include particle accelerators and tokamak reactors. Conventional fission power reactors also cause artificial transmutation, not from the power of the machine, but by exposing elements to neutrons produced by fission from an artificially produced nuclear chain reaction. For instance, when a uranium atom is bombarded with slow neutrons, fission takes place. This releases, on average, three neutrons and a large amount of energy. The released neutrons then cause fission of other uranium atoms, until all of the available uranium is exhausted. This is called a chain reaction.
Artificial nuclear transmutation has been considered as a possible mechanism for reducing the volume and hazard of radioactive waste.[2]
^Lehmann, W.M. (2000). "Transmutation in der Kerntechnik" [Nuclear Transmutation]. Elektrizitaetswirtschaft (in German). 99 (1–2). Frankfurt am Main: VWEW-Energieverlag GmbH: 51–52. ISSN 0013-5496. INIS 31018687.
^http://www.oecd-nea.org/trw/ "Transmutation of Radioactive Waste." Nuclear Energy Agency. Feb 3rd 2012.
and 28 Related for: Nuclear transmutation information
Nucleartransmutation is the conversion of one chemical element or an isotope into another chemical element. Nucleartransmutation occurs in any process...
philosopher's stone Mental transmutation, the transformation of a mental state Biological transmutation, the claim that nucleartransmutation occurs within living...
for gamma decay or internal conversion from a nuclear excited state, the decay is a nucleartransmutation resulting in a daughter containing a different...
greater than that of the starting element. Fission is a form of nucleartransmutation because the resulting fragments (or daughter atoms) are not the...
Resistance. Kervran proposed that nucleartransmutation occurs in living organisms, which he called "biological transmutation". He made this claim after doing...
in 1932 at Cambridge University, a fully artificial nuclear reaction and nucleartransmutation was achieved by Rutherford's colleagues John Cockcroft...
fusing small nuclei. Building on the early experiments in artificial nucleartransmutation by Patrick Blackett, laboratory fusion of hydrogen isotopes was...
of the neutron by James Chadwick in 1932 created a new means of nucleartransmutation. Enrico Fermi and his colleagues in Rome studied the results of...
processes, and transformations in the nuclei of atoms, such as nucleartransmutation and nuclear properties. It is the chemistry of radioactive elements such...
nuclear transmutation. Later, Rutherford's team, using protons from an accelerator, demonstrated artificially-induced nuclear reactions and transmutation. Rutherford...
known as nucleartransmutation. This new element has an unchanged mass number A, but an atomic number Z that is increased by one. As in all nuclear decays...
in large "proton-rich" radionuclides. Positron decay results in nucleartransmutation, changing an atom of one chemical element into an atom of an element...
absorbed in any nuclear transmutation, one must know the nuclear binding energies of the nuclear components involved in the transmutation. Electrons and nuclei...
reactors, including a small modular reactor, a liquid-metal fast/nucleartransmutation reactor, and a high-temperature hydrogen generation design. Fuel...
nuclear fusion-fission hybrids are proposed to make use of those neutrons to either maintain a subcritical reactor or to aid in nucleartransmutation...
induces electron or positron emission or absorption, thus causing nucleartransmutation. The Z boson mediates the transfer of momentum, spin and energy...
The element is not changed to another element in the process (no nucleartransmutation is involved). Other more exotic decays are possible (see the first...
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or a combination of fission...
waste, while re-use and transmutation are favored solutions for reducing the HLW inventory. Boundaries to recycling of spent nuclear fuel are regulatory and...
inside out. Moreover, as the fuel's composition changes through nucleartransmutation, fuel rods are continually reshuffled within the core to optimize...
became the first person to prove that radioactivity could cause the nucleartransmutation of one chemical element to another. He also made a major contribution...
Technologies for Separation and Transmutation", National Academy Press, Washington D.C. 1996. Processing of Used Nuclear Fuel, World Nuclear Association PUREX Process...
newly formed unbound system. When considering whether a specific nucleartransmutation, a reaction or a decay, is energetically allowed, one only needs...
produce what he later understood as a directed nucleartransmutation of one element to another. Transmutation of elements from one to another had been understood...
uranium-238, and uranium-235, spontaneous fission of uranium-238, and nucleartransmutation reactions induced by natural radioactivity, such as the production...
gold, is the traditional goal of alchemy. Such transmutation is possible in particle accelerators or nuclear reactors, although the production cost is currently...