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tritium (trĭtˈēəm), radioactive isotope of hydrogen with mass number 3. The tritium nucleus, called a triton, contains one proton and two neutrons. It has a half-life of 12.5 years and decays by beta-particle emission. The symbol is T or 3H. It is one form of heavy hydrogen, the other being deuterium. It is usually produced in nuclear reactors as a byproduct of the irradiation of lithium. Its current major use is to increase the yield of thermonuclear devices. The U.S. Department of Energy has a production reactor in Savannah, Georgia for this purpose. In the future, vast amounts of tritium will fuel experiments in fusion research. Canada, Europe and Japan have extensive programs underway to develop physics-based, as opposed to mechanical based, production procedures to generate the volumes necessary to proceed with these experiments.
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The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



(T, or 3H), a radioactive isotope of hydrogen with mass number 3 (hence its name, from the Greek tritos, “third”).

Tritium was discovered in 1934 by the British scientists E. Rutherford, M. L. Oliphant, and P. Harteck. The tritium nucleus consists of one proton and two neutrons. Tritium is β-active, with a half-life of 12.26 yr. In nature, it is formed in in-significant quantities by the action of the neutrons of cosmic rays on nitrogen atoms (147N + n = 31T + 126C) and in nuclear transformations induced by high-energy cosmic particles. The mean content of tritium in natural waters is one atom per 1018 atoms of !H.

Tritium is obtained in nuclear reactors by irradiation of 63Li with neutrons (63Li + n = 31T + 42He). It is used as the most important component in thermonuclear synthesis reactions, as a fuel in thermonuclear bombs, and in chemical, biological, and hydrological studies.


Evans, E. A. Tritii i ego soedineniia. Moscow, 1970. (Translated from English.)
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.


(nuclear physics)
The hydrogen isotope having mass number 3; it is one form of heavy hydrogen, the other being deuterium. Symbolized 3H; T.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.


a radioactive isotope of hydrogen, occurring in trace amounts in natural hydrogen and produced in a nuclear reactor. Tritiated compounds are used as tracers. Symbol: T or 3H; half-life: 12.5 years
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
References in periodicals archive ?
This 'closed-loop' system allows for the recycling and reuse of tritium as well as the ability to use it for further experiments - a valuable resource, therefore, for tritium R&D.
Note: What is this tritium that cannot be removed by ALPS?
In the United States, the Environmental Protection Agency (EPA) sets a maximum contaminant level for tritium at 20,000 picoCuries per liter (pCi/L).
Its VTAC sights feature a fiber-optic rod positioned above a tritium insert--a dot above a dot on the front sight as well as to either side of the rear sight notch.
Citing a recent commercial satellite picture, Hecker said North Korea is adding at least one more tritium production facility to an old facility.
The rise in demand for tritium light sources to be used in exit signs as well as mandatory, warning and regulatory signs used on the roadways is expected to be dynamic due to properties like resistance to oil, water or any corrosive materials.
Considering the leakage of the water in the secondary loop and the decay of H-3, the tritium inventory in the secondary loop can be calculated as
Tritium is an unstable isotope with a half-life of 12.32 years.
The application of this catalyst to the liquid phase catalytic exchange process[7], is expected to overcome significant technological hurdles with regards to improving the reliability and efficiency of systems for collecting tritium from tritiated water.
Smith and McKague developed a stable radiation-emitting material based on a silicone with tritium and a wavelength-shifter side chain (phosphor) bonded to the silicone.
Mortars use sighting devices that contain radioactive tritium. If one of these devices gets banged around and broken, the tritium can leak out.
(Tepco) has said that it has found raised levels of radioactive tritium in groundwater sample collected from a newly built observation well by the Pacific Ocean near the crippled Fukushima No.