51 relations: Arthur Jeffrey Dempster, Barium, Barn (unit), Boron, Cadmium, Chain reaction, Chemical element, Control rod, Critical mass, Delayed neutron, Electronvolt, Energy, Enriched uranium, Fissile material, Graphite-moderated reactor, Gun-type fission weapon, Hafnium, Half-life, Isotopes of neptunium, Isotopes of protactinium, Isotopes of thorium, Isotopes of uranium, Krypton, Light-water reactor, Little Boy, Mole (unit), Natural uranium, Neutron, Neutron capture, Neutron moderator, Neutron reflector, Neutron temperature, Nuclear cross section, Nuclear explosion, Nuclear fission, Nuclear fission product, Nuclear reactor, Nuclear weapon, Nuclear weapon design, Plutonium-239, Polonium, Popular Mechanics, Pressurized heavy-water reactor, Primordial nuclide, Radioactive decay, Tritium, Uranium, Uranium-234, Uranium-236, Uranium-238, ..., Weapons-grade nuclear material. Expand index (1 more) » « Shrink index
Arthur Jeffrey Dempster (August 14, 1886 – March 11, 1950) was a Canadian-American physicist best known for his work in mass spectrometry and his discovery of the uranium isotope 235U.
Barium is a chemical element with symbol Ba and atomic number 56.
A barn (symbol: b) is a unit of area equal to 10−28 m2 (100 fm2).
Boron is a chemical element with symbol B and atomic number 5.
Cadmium is a chemical element with symbol Cd and atomic number 48.
A chain reaction is a sequence of reactions where a reactive product or by-product causes additional reactions to take place.
A chemical element is a species of atoms having the same number of protons in their atomic nuclei (that is, the same atomic number, or Z).
Control rods are used in nuclear reactors to control the fission rate of uranium and plutonium.
A critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction.
In nuclear engineering, a delayed neutron is a neutron emitted after a nuclear fission event, by one of the fission products (or actually, a fission product daughter after beta decay), any time from a few milliseconds to a few minutes after the fission event.
In physics, the electronvolt (symbol eV, also written electron-volt and electron volt) is a unit of energy equal to approximately joules (symbol J).
In physics, energy is the quantitative property that must be transferred to an object in order to perform work on, or to heat, the object.
Enriched uranium is a type of uranium in which the percent composition of uranium-235 has been increased through the process of isotope separation.
In nuclear engineering, fissile material is material capable of sustaining a nuclear fission chain reaction.
A graphite reactor is a nuclear reactor that uses carbon as a neutron moderator, which allows un-enriched uranium to be used as nuclear fuel.
Gun-type fission weapons are fission-based nuclear weapons whose design assembles their fissile material into a supercritical mass by the use of the "gun" method: shooting one piece of sub-critical material into another.
Hafnium is a chemical element with symbol Hf and atomic number 72.
Half-life (symbol t1⁄2) is the time required for a quantity to reduce to half its initial value.
Neptunium (93Np) is usually considered an artificial element, although trace quantities are found in nature, so thus a standard atomic weight cannot be given.
Protactinium (91Pa) has no stable isotopes.
Although thorium (90Th) has 6 naturally occurring isotopes, none of these isotopes are stable; however, one isotope, 232Th, is relatively stable, with a half-life of 1.405×1010 years, considerably longer than the age of the Earth, and even slightly longer than the generally accepted age of the universe.
Uranium (92U) is a naturally occurring radioactive element that has no stable isotopes but two primordial isotopes (uranium-238 and uranium-235) that have long half-life and are found in appreciable quantity in the Earth's crust, along with the decay product uranium-234.
Krypton (from translit "the hidden one") is a chemical element with symbol Kr and atomic number 36.
The light-water reactor (LWR) is a type of thermal-neutron reactor that uses normal water, as opposed to heavy water, as both its coolant and neutron moderator – furthermore a solid form of fissile elements is used as fuel.
"Little Boy" was the codename for the atomic bomb dropped on the Japanese city of Hiroshima on 6 August 1945 during World War II by the Boeing B-29 Superfortress Enola Gay, piloted by Colonel Paul W. Tibbets, Jr., commander of the 509th Composite Group of the United States Army Air Forces.
The mole, symbol mol, is the SI unit of amount of substance.
Natural uranium (NU, Unat) refers to uranium with the same isotopic ratio as found in nature.
Neutron capture is a nuclear reaction in which an atomic nucleus and one or more neutrons collide and merge to form a heavier nucleus.
In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235 or a similar fissile nuclide.
A neutron reflector is any material that reflects neutrons.
The neutron detection temperature, also called the neutron energy, indicates a free neutron's kinetic energy, usually given in electron volts.
The nuclear cross section of a nucleus is used to characterize the probability that a nuclear reaction will occur.
A nuclear explosion is an explosion that occurs as a result of the rapid release of energy from a high-speed nuclear reaction.
In nuclear physics and nuclear chemistry, nuclear fission is either a nuclear reaction or a radioactive decay process in which the nucleus of an atom splits into smaller parts (lighter nuclei).
Nuclear fission products are the atomic fragments left after a large atomic nucleus undergoes nuclear fission.
A nuclear reactor, formerly known as an atomic pile, is a device used to initiate and control a self-sustained nuclear chain reaction.
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or from a combination of fission and fusion reactions (thermonuclear bomb).
Nuclear weapon designs are physical, chemical, and engineering arrangements that cause the physics package of a nuclear weapon to detonate.
Plutonium-239 is an isotope of plutonium.
Polonium is a chemical element with symbol Po and atomic number 84.
Popular Mechanics is a classic magazine of popular science and technology.
A pressurized heavy-water reactor (PHWR) is a nuclear reactor, commonly using natural uranium as its fuel, that uses heavy water (deuterium oxide D2O) as its coolant and neutron moderator.
In geochemistry, geophysics and geonuclear physics, primordial nuclides, also known as primordial isotopes, are nuclides found on Earth that have existed in their current form since before Earth was formed.
Radioactive decay (also known as nuclear decay or radioactivity) is the process by which an unstable atomic nucleus loses energy (in terms of mass in its rest frame) by emitting radiation, such as an alpha particle, beta particle with neutrino or only a neutrino in the case of electron capture, gamma ray, or electron in the case of internal conversion.
Tritium (or; symbol or, also known as hydrogen-3) is a radioactive isotope of hydrogen.
Uranium is a chemical element with symbol U and atomic number 92.
Uranium-234 is an isotope of uranium.
Uranium-236 is an isotope of uranium that is neither fissile with thermal neutrons, nor very good fertile material, but is generally considered a nuisance and long-lived radioactive waste.
Uranium-238 (238U or U-238) is the most common isotope of uranium found in nature, with a relative abundance of 99%.
Weapons-grade nuclear material is any fissionable nuclear material that is pure enough to be used to make a nuclear weapon or has properties that make it particularly suitable for nuclear weapons use.