CobaltCobalt is a chemical element with the symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silver metal. Cobalt-based blue pigments (cobalt blue) have been used since ancient times for jewelry and paints, and to impart a distinctive blue tint to glass, but the color was for a long time thought to be due to the known metal bismuth.
External beam radiotherapyExternal beam radiation therapy (EBRT) is a compound word that refers to the use of a collimated beam of ionizing radiation from outside the body to treat a disease. external—from outside the body, beam—shaped by collimation, radiation—ionizing radiation, therapy—used to treat disease The word teletherapy has the same meaning as external beam radiation therapy with the tele- empahasizing that it is treatment from a distance. Radiation and therapy are commonly shortened into the portmanteau radiotherapy.
Gamma rayA gamma ray, also known as gamma radiation (symbol γ or ), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves, typically shorter than those of X-rays. With frequencies above 30 exahertz (3e19Hz), it imparts the highest photon energy. Paul Villard, a French chemist and physicist, discovered gamma radiation in 1900 while studying radiation emitted by radium.
Dirty bombA dirty bomb or radiological dispersal device is a radiological weapon that combines radioactive material with conventional explosives. The purpose of the weapon is to contaminate the area around the dispersal agent/conventional explosion with radioactive material, serving primarily as an area denial device against civilians. It is not to be confused with a nuclear explosion, such as a fission bomb, which produces blast effects far in excess of what is achievable by the use of conventional explosives.
Caesium-137Caesium-137 (), cesium-137 (US), or radiocaesium, is a radioactive isotope of caesium that is formed as one of the more common fission products by the nuclear fission of uranium-235 and other fissionable isotopes in nuclear reactors and nuclear weapons. Trace quantities also originate from spontaneous fission of uranium-238. It is among the most problematic of the short-to-medium-lifetime fission products.
Cobalt bombA cobalt bomb is a type of "salted bomb": a nuclear weapon designed to produce enhanced amounts of radioactive fallout, intended to contaminate a large area with radioactive material, potentially for the purpose of radiological warfare, mutual assured destruction or as doomsday devices. The concept of a cobalt bomb was originally described in a radio program by physicist Leó Szilárd on February 26, 1950. His intent was not to propose that such a weapon be built, but to show that nuclear weapon technology would soon reach the point where it could end human life on Earth, a doomsday device.
Neutron activationNeutron activation is the process in which neutron radiation induces radioactivity in materials, and occurs when atomic nuclei capture free neutrons, becoming heavier and entering excited states. The excited nucleus decays immediately by emitting gamma rays, or particles such as beta particles, alpha particles, fission products, and neutrons (in nuclear fission). Thus, the process of neutron capture, even after any intermediate decay, often results in the formation of an unstable activation product.
Salted bombA salted bomb is a nuclear weapon designed to function as a radiological weapon by producing larger quantities of radioactive fallout than unsalted nuclear arms. This fallout can render a large area uninhabitable. The term is derived both from the means of their manufacture, which involves the incorporation of additional elements to a standard atomic weapon, and from the expression "to salt the earth", meaning to render an area uninhabitable for generations. The idea originated with Hungarian-American physicist Leo Szilard, in February 1950.
Particle acceleratorA particle accelerator is a machine that uses electromagnetic fields to propel charged particles to very high speeds and energies, and to contain them in well-defined beams. Large accelerators are used for fundamental research in particle physics. The largest accelerator currently active is the Large Hadron Collider (LHC) near Geneva, Switzerland, operated by the CERN. It is a collider accelerator, which can accelerate two beams of protons to an energy of 6.5 TeV and cause them to collide head-on, creating center-of-mass energies of 13 TeV.
Induced radioactivityInduced radioactivity, also called artificial radioactivity or man-made radioactivity, is the process of using radiation to make a previously stable material radioactive. The husband and wife team of Irène Joliot-Curie and Frédéric Joliot-Curie discovered induced radioactivity in 1934, and they shared the 1935 Nobel Prize in Chemistry for this discovery. Irène Curie began her research with her parents, Marie Curie and Pierre Curie, studying the natural radioactivity found in radioactive isotopes.