Various
radionuclide
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess numbers of either neutrons or protons, giving it excess nuclear energy, and making it unstable. This excess energy can be used in one of three ...
s emit
beta particle
A beta particle, also called beta ray or beta radiation (symbol β), is a high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic nucleus, known as beta decay. There are two forms of beta decay, β− decay and � ...
s (high-speed electrons or positrons) through
radioactive decay
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is conside ...
of their atomic nucleus. These can be used in a range of different industrial, scientific, and medical applications. This article lists some common beta-emitting radionuclides of technological importance, and their properties.
Fission products
Strontium
Strontium-90
Strontium-90 () is a radioactive isotope of strontium produced by nuclear fission, with a half-life of 28.79 years. It undergoes β− decay into yttrium-90, with a decay energy of 0.546 MeV. Strontium-90 has applications in medicine a ...
is a commonly used
beta
Beta (, ; uppercase , lowercase , or cursive ; or ) is the second letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Ancient Greek, beta represented the voiced bilabial plosive . In Modern Greek, it represe ...
emitter used in industrial sources. It decays to
yttrium-90
Yttrium-90 () is a radioactive isotope of yttrium. Yttrium-90 has found a wide range of uses in radiation therapy to treat some forms of cancer
Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the ...
, which is itself a beta emitter. It is also used as a thermal power source in
radioisotope thermoelectric generator
A radioisotope thermoelectric generator (RTG, RITEG), or radioisotope power system (RPS), is a type of nuclear battery that uses an array of thermocouples to convert the Decay heat, heat released by the decay of a suitable radioactive material i ...
(RTG) power packs. These use heat produced by radioactive decay of strontium-90 to generate heat, which can be converted to electricity using a thermocouple. Strontium-90 has a shorter half-life, produces less power, and requires more shielding than
plutonium-238
Plutonium-238 ( or Pu-238) is a radioactive isotope of plutonium that has a half-life of 87.7 years.
Plutonium-238 is a very powerful alpha emitter; as alpha particles are easily blocked, this makes the plutonium-238 isotope suitable for usage ...
, but is cheaper as it is a fission product and is present in a high concentration in
nuclear waste
Radioactive waste is a type of hazardous waste that contains radioactive material. It is a result of many activities, including nuclear medicine, nuclear research, nuclear power generation, nuclear decommissioning, rare-earth mining, and nuclear ...
and can be relatively easily chemically extracted. Strontium-90 based RTGs have been used to power remote
lighthouses. As strontium is water-soluble, the
perovskite
Perovskite (pronunciation: ) is a calcium titanium oxide mineral composed of calcium titanate (chemical formula ). Its name is also applied to the class of compounds which have the same type of crystal structure as , known as the perovskite (stru ...
form
strontium titanate is usually employed as it is not water-soluble and has a high melting point.
Strontium-89 is a short-lived beta emitter which has been used as a treatment for
bone tumors; it is used in
palliative care
Palliative care (from Latin root "to cloak") is an interdisciplinary medical care-giving approach aimed at optimizing quality of life and mitigating or reducing suffering among people with serious, complex, and often terminal illnesses. Man ...
in terminal
cancer
Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Po ...
cases. Both strontium-89 and strontium-90 are
fission products.
Neutron activation products
Tritium
Tritium
Tritium () or hydrogen-3 (symbol T or H) is a rare and radioactive isotope of hydrogen with a half-life of ~12.33 years. The tritium nucleus (t, sometimes called a ''triton'') contains one proton and two neutrons, whereas the nucleus of the ...
is a low-energy beta emitter commonly used as a
radiotracer in research and in
self-powered lighting
Tritium radioluminescence is the use of gaseous tritium, a radioactive isotope of hydrogen, to create visible light. Tritium emits electrons through beta decay and, when they interact with a phosphor material, light is emitted through the proc ...
. The half-life of tritium is 12.3 years. The
electron
The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary charge, elementary electric charge. It is a fundamental particle that comprises the ordinary matter that makes up the universe, along with up qua ...
s from
beta
Beta (, ; uppercase , lowercase , or cursive ; or ) is the second letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Ancient Greek, beta represented the voiced bilabial plosive . In Modern Greek, it represe ...
emission from tritium are so low in energy (average decay energy 5.7 keV) that a
Geiger counter
A Geiger counter (, ; also known as a Geiger–Müller counter or G-M counter) is an electronic instrument for detecting and measuring ionizing radiation with the use of a Geiger–Müller tube. It is widely used in applications such as radiat ...
cannot be used to detect them. An advantage of the low energy of the decay is that it is easy to shield, since the low-energy electrons penetrate only to shallow depths, reducing the safety issues in deal with the isotope.
Tritium can also be found in
metal work in the form of a tritiated
rust
Rust is an iron oxide, a usually reddish-brown oxide formed by the reaction of iron and oxygen in the catalytic presence of water or air moisture. Rust consists of hydrous iron(III) oxides (Fe2O3·nH2O) and iron(III) oxide-hydroxide (FeO(OH) ...
, this can be treated by heating the
steel
Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...
in a
furnace to drive off the tritium-containing water.
Tritium can be made by the
neutron irradiation of
lithium
Lithium (from , , ) is a chemical element; it has chemical symbol, symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard temperature and pressure, standard conditions, it is the least dense metal and the ...
.
Carbon
Carbon-14
Carbon-14, C-14, C or radiocarbon, is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons. Its presence in organic matter is the basis of the radiocarbon dating method pioneered by Willard Libby and coll ...
is also commonly used as a beta source in research, it is commonly used as a
radiotracer in organic compounds. While the energy of the beta particles is higher than those of tritium they are still quite low in energy. For instance the walls of a glass bottle absorb it. Carbon-14 is made by the
np reaction of
nitrogen
Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...
-14 with neutrons. It is generated in the atmosphere by the action of
cosmic rays
Cosmic rays or astroparticles are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar ...
on nitrogen. Also a large amount was generated by the neutrons from the
air burst
An air burst or airburst is the detonation of an explosive device such as an anti-personnel artillery shell or a nuclear weapon in the air instead of on contact with the ground or target. The principal military advantage of an air burst over ...
s during
nuclear weapons testing
Nuclear weapons tests are experiments carried out to determine the performance of nuclear weapons and the effects of Nuclear explosion, their explosion. Nuclear testing is a sensitive political issue. Governments have often performed tests to si ...
conducted in the 20th century. The
specific activity
Specific activity (symbol ''a'') is the activity per unit mass of a radionuclide and is a physical property of that radionuclide.
It is usually given in units of becquerel per kilogram (Bq/kg), but another commonly used unit of specific activi ...
of atmospheric carbon increased as a result of the
nuclear testing
Nuclear weapons tests are experiments carried out to determine the performance of nuclear weapons and the effects of Nuclear explosion, their explosion. Nuclear testing is a sensitive political issue. Governments have often performed tests to si ...
but due to the exchange of carbon between the air and other parts of the
carbon cycle
The carbon cycle is a part of the biogeochemical cycle where carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of Earth. Other major biogeochemical cycles include the nitrogen cycle and the water cycl ...
it has now returned to a very low value. For small amounts of carbon-14, one of the favoured
disposal methods is to burn the waste in a medical
incinerator
Incineration is a list of solid waste treatment technologies, waste treatment process that involves the combustion of substances contained in waste materials. Industrial plants for waste incineration are commonly referred to as waste-to-ene ...
, the idea is that by dispersing the radioactivity over a very wide area the threat to any one human is very small.
Phosphorus
Phosphorus-32
Phosphorus-32 (32P) is a radioactive isotope of phosphorus. The nucleus of phosphorus-32 contains 15 protons and 17 neutrons, one more neutron than the most common isotope of phosphorus, phosphorus-31. Phosphorus-32 only exists in small quantiti ...
is a short-lived high energy beta emitter, which is used in research in radiotracers. It has a half-life of 14 days. It can be used in
DNA
Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...
research.
Phosphorus
Phosphorus is a chemical element; it has Chemical symbol, symbol P and atomic number 15. All elemental forms of phosphorus are highly Reactivity (chemistry), reactive and are therefore never found in nature. They can nevertheless be prepared ar ...
-32 can be made by the neutron irradiation (np reaction) of
sulfur
Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...
-32 or from
phosphorus
Phosphorus is a chemical element; it has Chemical symbol, symbol P and atomic number 15. All elemental forms of phosphorus are highly Reactivity (chemistry), reactive and are therefore never found in nature. They can nevertheless be prepared ar ...
-31 by
neutron capture
Neutron capture is a nuclear reaction in which an atomic nucleus and one or more neutrons collide and merge to form a heavier nucleus. Since neutrons have no electric charge, they can enter a nucleus more easily than positively charged protons, wh ...
.
Nickel
Nickel-63 is a radioisotope of nickel that can be used as an energy source in
Radioisotope Piezoelectric Generators. It has a half-life of 100.1 years. It can be created by irradiating
nickel-62
Nickel-62 is an isotope of nickel having 28 protons and 34 neutrons.
It is a stable isotope, with the highest binding energy per nucleon of any known nuclide (8.7945 MeV). It is often stated that 56Fe is the "most stable nucleus", but only beca ...
with neutrons in a nuclear reactor.
See also
*
Betavoltaic device
*
Commonly used gamma-emitting isotopes
*
List of alpha-emitting nuclides
References
{{Reflist
External links
List of Pure Beta Emitters (U. Wisconsin Madison)
Isotopes
Nuclear chemistry
Nuclear materials
Nuclear physics
Radioactivity