288 relations: Abraham Pais, Actinide, Air shower (physics), Alpha decay, Alpha particle, Annihilation, Antineutron, Antiparticle, Antiproton, Astroparticle Physics (journal), Atom, Atomic nucleus, Atomic number, Atomic orbital, Baryon, Baryon number, Benjamin W. Lee, Berkeley, California, Beryllium, Beta decay, Beta particle, Binding energy, Bohr magneton, Boosted fission weapon, Borehole, Boron, Breeder reactor, Bremsstrahlung, Bruce Cork, Cabibbo–Kobayashi–Maskawa matrix, Californium, Cambridge, Cambridge University Press, CANDU reactor, Carbon, Carbon-12, Carbon-13, Carbon-14, Cavendish Laboratory, Cell (biology), Chain reaction, Chemical element, Chemical reaction, Chicago Pile-1, Cloud chamber, Color charge, Condensed matter physics, Conservation law, Contemporary Physics, Copper-64, ..., Cosmic ray, CPT symmetry, Cross section (physics), CryoEDM, Dark matter, Decay energy, Degenerate matter, Depleted uranium, Deuterium, Dirac equation, Down quark, Elastic scattering, Electric charge, Electric dipole moment, Electric field, Electromagnetism, Electron, Electron capture, Electron neutrino, Electronvolt, Elementary charge, Elementary particle, Energy density, Energy level, Enrico Fermi, Ernest Rutherford, Exponential decay, Faraday effect, Fast-neutron reactor, Felix Bloch, Femtometre, Fermi's interaction, Fermion, Fertile material, First principle, Fissile material, Flavour (particle physics), Fluorine, Frédéric Joliot-Curie, Free neutron decay, Fritz Strassmann, Fusion power, Gamma ray, Gluon, Graphite, Gravity, Greek language, Hadron, Half-life, Heavy water, Helium, Helium-3, Herwig Schopper, Hydrogen, Hydrogen atom, Institut Laue–Langevin, Intrinsic parity, Introduction to quantum mechanics, Inverse beta decay, Ionization, Ionization energy, Ionizing radiation, Irène Joliot-Curie, Irradiation, Isobar (nuclide), Isospin, Isotone, Isotope, Isotopes of antimony, Isotopes of helium, Isotopes of lithium, Isotopes of nitrogen, James Chadwick, Jeremy Bernstein, Joule, Journal of Geophysical Research, Kinetic energy, Kinetic theory of gases, Klein paradox, Latin, Lead, Light-water reactor, Lise Meitner, List of particles, Lithium, Luis Walter Alvarez, Macmillan Publishers (United States), Magnet, Magnetic field, Mass, Mass number, Mass spectrometry, Mass–energy equivalence, Maurice Goldhaber, Maxwell–Boltzmann distribution, Mode (statistics), Molecule, Muon, Natural logarithm, Nature (journal), Neutrino, Neutron, Neutron activation, Neutron activation analysis, Neutron bomb, Neutron capture, Neutron capture nucleosynthesis, Neutron capture therapy of cancer, Neutron diffraction, Neutron emission, Neutron flux, Neutron generator, Neutron magnetic moment, Neutron moderator, Neutron number, Neutron probe, Neutron radiation, Neutron reflector, Neutron research facility, Neutron scattering, Neutron source, Neutron star, Neutron supermirror, Neutron temperature, Neutron tomography, Neutron transport, Neutron-velocity selector, Neutron–proton ratio, Neutronium, Nobel Foundation, Nobel Prize in Chemistry, Nobel Prize in Physics, Nuclear chain reaction, Nuclear fission, Nuclear force, Nuclear fuel, Nuclear fusion, Nuclear magneton, Nuclear physics, Nuclear proliferation, Nuclear reaction, Nuclear reactor, Nuclear shell model, Nuclear transmutation, Nuclear weapon, Nuclear weapon design, Nucleon, Nucleosynthesis, Nuclide, Nuovo Cimento, Oscar W. Greenberg, Oskar Klein, Otto Hahn, Oxford University Press, Paraffin wax, Particle accelerator, Paul Scherrer Institute, Pauli exclusion principle, Photodisintegration, Photon, Phys.org, Physical Review, Physical Review Letters, Physics beyond the Standard Model, Planck constant, Plutonium-239, Polonium, Positron, Positron emission, Potential energy, Proceedings of the Royal Society, Prompt gamma neutron activation analysis, Proton, Quantum mechanics, Quantum number, Quark, Quark model, R-process, Radiation, Radiation therapy, Radioactive decay, Radionuclide, Radius, Reactor-grade plutonium, Research reactor, Resonance, S-process, Shin'ichirō Tomonaga, Sievert, Spallation, Spallation Neutron Source, Special relativity, Speed of light, Spin (physics), Spin-½, Spontaneous fission, Springer Science+Business Media, Stable nuclide, Standard deviation, Standard Model, Star, Startup neutron source, Stern–Gerlach experiment, Strong interaction, SU(6) (physics), Subatomic particle, Surface exposure dating, Symbol (chemistry), Synonym, Table of nuclides, Tesla (unit), Tetraneutron, The Science of Nature, Thermal-neutron reactor, Thermonuclear weapon, Thorium fuel cycle, Tin, Tokamak, Total angular momentum quantum number, Transient state, Trinity (nuclear test), Tritium, Ultracold neutrons, Uncertainty principle, Unified atomic mass unit, University of Sussex, University of Tokyo, Up quark, Uranium-233, Uranium-235, W and Z bosons, Walther Bothe, Water, Wave function, Weak interaction, Werner Heisenberg, X-ray, Zeitschrift für Physik. Expand index (238 more) » « Shrink index
Abraham Pais (May 19, 1918 – July 28, 2000) was a Dutch-born American physicist and science historian.
The actinide or actinoid (IUPAC nomenclature) series encompasses the 15 metallic chemical elements with atomic numbers from 89 to 103, actinium through lawrencium.
An air shower is an extensive (many kilometres wide) cascade of ionized particles and electromagnetic radiation produced in the atmosphere when a primary cosmic ray (i.e. one of extraterrestrial origin) enters the atmosphere.
Alpha decay or α-decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus) and thereby transforms or 'decays' into an atom with a mass number that is reduced by four and an atomic number that is reduced by two.
Alpha particles consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus.
In particle physics, annihilation is the process that occurs when a subatomic particle collides with its respective antiparticle to produce other particles, such as an electron colliding with a positron to produce two photons.
The antineutron is the antiparticle of the neutron with symbol.
In particle physics, every type of particle has an associated antiparticle with the same mass but with opposite physical charges (such as electric charge).
The antiproton,, (pronounced p-bar) is the antiparticle of the proton.
Astroparticle Physics is a peer-reviewed scientific journal covering experimental and theoretical research in the interacting fields of cosmic ray physics, astronomy and astrophysics, cosmology, and particle physics.
An atom is the smallest constituent unit of ordinary matter that has the properties of a chemical element.
The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden gold foil experiment.
The atomic number or proton number (symbol Z) of a chemical element is the number of protons found in the nucleus of an atom.
In quantum mechanics, an atomic orbital is a mathematical function that describes the wave-like behavior of either one electron or a pair of electrons in an atom.
A baryon is a composite subatomic particle made up of three quarks (a triquark, as distinct from mesons, which are composed of one quark and one antiquark).
In particle physics, the baryon number is a strictly conserved additive quantum number of a system.
Benjamin Whisoh Lee (January 1, 1935 – June 16, 1977) or Ben Lee, was a Korean-born American theoretical physicist.
Berkeley is a city on the east shore of San Francisco Bay in northern Alameda County, California.
Beryllium is a chemical element with symbol Be and atomic number 4.
In nuclear physics, beta decay (β-decay) is a type of radioactive decay in which a beta ray (fast energetic electron or positron) and a neutrino are emitted from an atomic nucleus.
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 during the process of beta decay.
Binding energy (also called separation energy) is the minimum energy required to disassemble a system of particles into separate parts.
In atomic physics, the Bohr magneton (symbol μB) is a physical constant and the natural unit for expressing the magnetic moment of an electron caused by either its orbital or spin angular momentum.
A boosted fission weapon usually refers to a type of nuclear bomb that uses a small amount of fusion fuel to increase the rate, and thus yield, of a fission reaction.
A borehole is a narrow shaft bored in the ground, either vertically or horizontally.
Boron is a chemical element with symbol B and atomic number 5.
A breeder reactor is a nuclear reactor that generates more fissile material than it consumes.
Bremsstrahlung, from bremsen "to brake" and Strahlung "radiation"; i.e., "braking radiation" or "deceleration radiation", is electromagnetic radiation produced by the deceleration of a charged particle when deflected by another charged particle, typically an electron by an atomic nucleus.
Bruce Cork (1916 – October 7, 1994) was a physicist who discovered the antineutron in 1956 while working at the Lawrence Berkeley National Laboratory.
In the Standard Model of particle physics, the Cabibbo–Kobayashi–Maskawa matrix, CKM matrix, quark mixing matrix, or KM matrix is a unitary matrix which contains information on the strength of flavour-changing weak decays.
Californium is a radioactive chemical element with symbol Cf and atomic number 98.
Cambridge is a university city and the county town of Cambridgeshire, England, on the River Cam approximately north of London.
Cambridge University Press (CUP) is the publishing business of the University of Cambridge.
The CANDU, for Canada Deuterium Uranium, is a Canadian pressurized heavy-water reactor design used to generate electric power.
Carbon (from carbo "coal") is a chemical element with symbol C and atomic number 6.
Carbon-12 is the more abundant of the two stable isotopes of carbon (Carbon-13 being the other), amounting to 98.93% of the element carbon; its abundance is due to the triple-alpha process by which it is created in stars.
Carbon-13 (13C) is a natural, stable isotope of carbon with a nucleus containing six protons and seven neutrons.
Carbon-14, 14C, or radiocarbon, is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons.
The Cavendish Laboratory is the Department of Physics at the University of Cambridge, and is part of the School of Physical Sciences.
The cell (from Latin cella, meaning "small room") is the basic structural, functional, and biological unit of all known living organisms.
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).
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another.
Chicago Pile-1 (CP-1) was the world's first nuclear reactor.
A Cloud Chamber, also known as a Wilson Cloud Chamber, is a particle detector used for visualizing the passage of ionizing radiation.
Color charge is a property of quarks and gluons that is related to the particles' strong interactions in the theory of quantum chromodynamics (QCD).
Condensed matter physics is the field of physics that deals with the macroscopic and microscopic physical properties of matter.
In physics, a conservation law states that a particular measurable property of an isolated physical system does not change as the system evolves over time.
Contemporary Physics is a peer-reviewed scientific journal publishing introductory articles on important recent developments in physics.
Copper-64 is a positron emitting isotope of copper, with applications for molecular radiotherapy and positron emission tomography.
Cosmic rays are high-energy radiation, mainly originating outside the Solar System and even from distant galaxies.
Charge, parity, and time reversal symmetry is a fundamental symmetry of physical laws under the simultaneous transformations of charge conjugation (C), parity transformation (P), and time reversal (T).
When two particles interact, their mutual cross section is the area transverse to their relative motion within which they must meet in order to scatter from each other.
CryoEDM is a particle physics experiment aiming to measure the electric dipole moment (EDM) of the neutron to a precision of ~10−28ecm.
Dark matter is a theorized form of matter that is thought to account for approximately 80% of the matter in the universe, and about a quarter of its total energy density.
The decay energy is the energy released by a radioactive decay.
Degenerate matter is a highly dense state of matter in which particles must occupy high states of kinetic energy in order to satisfy the Pauli exclusion principle.
Depleted uranium (DU; also referred to in the past as Q-metal, depletalloy or D-38) is uranium with a lower content of the fissile isotope U-235 than natural uranium.
Deuterium (or hydrogen-2, symbol or, also known as heavy hydrogen) is one of two stable isotopes of hydrogen (the other being protium, or hydrogen-1).
In particle physics, the Dirac equation is a relativistic wave equation derived by British physicist Paul Dirac in 1928.
The down quark or d quark (symbol: d) is the second-lightest of all quarks, a type of elementary particle, and a major constituent of matter.
Elastic scattering is a form of particle scattering in scattering theory, nuclear physics and particle physics.
Electric charge is the physical property of matter that causes it to experience a force when placed in an electromagnetic field.
The electric dipole moment is a measure of the separation of positive and negative electrical charges within a system, that is, a measure of the system's overall polarity.
An electric field is a vector field surrounding an electric charge that exerts force on other charges, attracting or repelling them.
Electromagnetism is a branch of physics involving the study of the electromagnetic force, a type of physical interaction that occurs between electrically charged particles.
The electron is a subatomic particle, symbol or, whose electric charge is negative one elementary charge.
Electron capture (K-electron capture, also K-capture, or L-electron capture, L-capture) is a process in which the proton-rich nucleus of an electrically neutral atom absorbs an inner atomic electron, usually from the K or L electron shell.
The electron neutrino is a subatomic lepton elementary particle which has no net electric charge.
In physics, the electronvolt (symbol eV, also written electron-volt and electron volt) is a unit of energy equal to approximately joules (symbol J).
The elementary charge, usually denoted as or sometimes, is the electric charge carried by a single proton, or equivalently, the magnitude of the electric charge carried by a single electron, which has charge.
In particle physics, an elementary particle or fundamental particle is a particle with no substructure, thus not composed of other particles.
Energy density is the amount of energy stored in a given system or region of space per unit volume.
A quantum mechanical system or particle that is bound—that is, confined spatially—can only take on certain discrete values of energy.
Enrico Fermi (29 September 1901 – 28 November 1954) was an Italian-American physicist and the creator of the world's first nuclear reactor, the Chicago Pile-1.
Ernest Rutherford, 1st Baron Rutherford of Nelson, HFRSE LLD (30 August 1871 – 19 October 1937) was a New Zealand-born British physicist who came to be known as the father of nuclear physics.
A quantity is subject to exponential decay if it decreases at a rate proportional to its current value.
In physics, the Faraday effect or Faraday rotation is a magneto-optical phenomenon—that is, an interaction between light and a magnetic field in a medium.
A fast-neutron reactor or simply a fast reactor is a category of nuclear reactor in which the fission chain reaction is sustained by fast neutrons, as opposed to thermal neutrons used in thermal-neutron reactors.
Felix Bloch (23 October 1905 – 10 September 1983) was a Swiss physicist, working mainly in the U.S. He and Edward Mills Purcell were awarded the 1952 Nobel Prize for Physics for "their development of new ways and methods for nuclear magnetic precision measurements."Sohlman, M (Ed.) Nobel Foundation directory 2003. Vastervik, Sweden: AB CO Ekblad; 2003.
The femtometre (American spelling femtometer, symbol fm derived from the Danish and Norwegian word femten, "fifteen"+Ancient Greek: μέτρον, metrοn, "unit of measurement") is an SI unit of length equal to 10−15 metres, which means a quadrillionth of one.
In particle physics, Fermi's interaction (also the Fermi theory of beta decay) is an explanation of the beta decay, proposed by Enrico Fermi in 1933.
In particle physics, a fermion is a particle that follows Fermi–Dirac statistics.
Fertile material is a material that, although not itself fissionable by thermal neutrons, can be converted into a fissile material by neutron absorption and subsequent nuclei conversions.
A first principle is a basic, foundational, self-evident proposition or assumption that cannot be deduced from any other proposition or assumption.
In nuclear engineering, fissile material is material capable of sustaining a nuclear fission chain reaction.
In particle physics, flavour or flavor refers to the species of an elementary particle.
Fluorine is a chemical element with symbol F and atomic number 9.
Jean Frédéric Joliot-Curie (19 March 1900 – 14 August 1958), born Jean Frédéric Joliot, was a French physicist, husband of Irène Joliot-Curie with whom he was jointly awarded the Nobel Prize in Chemistry.
Outside the nucleus, free neutrons are unstable and have a mean lifetime of (about 14 minutes, 42 seconds).
Friedrich Wilhelm "Fritz" Strassmann (Straßmann; 22 February 1902 – 22 April 1980) was a German chemist who, with Otto Hahn in early 1939, identified barium in the residue after bombarding uranium with neutrons, results which, when confirmed, demonstrated the previously unknown phenomenon of nuclear fission.
Fusion power is a form of power generation in which energy is generated by using fusion reactions to produce heat for electricity generation.
A gamma ray or gamma radiation (symbol γ or \gamma), is penetrating electromagnetic radiation arising from the radioactive decay of atomic nuclei.
A gluon is an elementary particle that acts as the exchange particle (or gauge boson) for the strong force between quarks.
Graphite, archaically referred to as plumbago, is a crystalline allotrope of carbon, a semimetal, a native element mineral, and a form of coal.
Gravity, or gravitation, is a natural phenomenon by which all things with mass or energy—including planets, stars, galaxies, and even light—are brought toward (or gravitate toward) one another.
Greek (Modern Greek: ελληνικά, elliniká, "Greek", ελληνική γλώσσα, ellinikí glóssa, "Greek language") is an independent branch of the Indo-European family of languages, native to Greece and other parts of the Eastern Mediterranean and the Black Sea.
In particle physics, a hadron (ἁδρός, hadrós, "stout, thick") is a composite particle made of quarks held together by the strong force in a similar way as molecules are held together by the electromagnetic force.
Half-life (symbol t1⁄2) is the time required for a quantity to reduce to half its initial value.
Heavy water (deuterium oxide) is a form of water that contains a larger than normal amount of the hydrogen isotope deuterium (or D, also known as heavy hydrogen), rather than the common hydrogen-1 isotope (or H, also called protium) that makes up most of the hydrogen in normal water.
Helium (from lit) is a chemical element with symbol He and atomic number 2.
Helium-3 (He-3, also written as 3He, see also helion) is a light, non-radioactive isotope of helium with two protons and one neutron (common helium having two protons and two neutrons).
Herwig Franz Schopper, (born on 28 February 1924) is an experimental physicist and was the Director General of CERN from 1981 to 1988.
Hydrogen is a chemical element with symbol H and atomic number 1.
A hydrogen atom is an atom of the chemical element hydrogen.
The Institut Laue–Langevin (ILL) is an internationally financed scientific facility, situated on the Polygone Scientifique in Grenoble, France.
In quantum mechanics, the intrinsic parity is a phase factor that arises as an eigenvalue of the parity operation x_i \rightarrow x_i'.
Quantum mechanics is the science of the very small.
Inverse beta decay, commonly abbreviated to IBD, is a nuclear reaction involving electron antineutrino scattering off a proton, creating a positron and a neutron.
Ionization or ionisation, is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons to form ions, often in conjunction with other chemical changes.
The ionization energy (Ei) is qualitatively defined as the amount of energy required to remove the most loosely bound electron, the valence electron, of an isolated gaseous atom to form a cation.
Ionizing radiation (ionising radiation) is radiation that carries enough energy to liberate electrons from atoms or molecules, thereby ionizing them.
Irène Joliot-Curie (12 September 1897 – 17 March 1956) was a French scientist, the daughter of Marie Curie and Pierre Curie and the wife of Frédéric Joliot-Curie.
Irradiation is the process by which an object is exposed to radiation.
Isobars are atoms (nuclides) of different chemical elements that have the same number of nucleons.
In nuclear physics and particle physics, isospin is a quantum number related to the strong interaction.
Two nuclides are isotones if they have the same neutron number N, but different proton number Z. For example, boron-12 and carbon-13 nuclei both contain 7 neutrons, and so are isotones.
Isotopes are variants of a particular chemical element which differ in neutron number.
Antimony (51Sb) occurs in two stable isotopes, 121Sb and 123Sb.
Although there are nine known isotopes of helium (2He) (standard atomic weight), only helium-3 and helium-4 are stable.
Naturally occurring lithium (3Li) is composed of two stable isotopes, lithium-6 and lithium-7, with the latter being far more abundant: about 92.5 percent of the atoms.
Natural nitrogen (7N) consists of two stable isotopes, nitrogen-14, which makes up the vast majority of naturally occurring nitrogen, and nitrogen-15, which is less common.
Sir James Chadwick, (20 October 1891 – 24 July 1974) was an English physicist who was awarded the 1935 Nobel Prize in Physics for his discovery of the neutron in 1932.
Jeremy Bernstein (born December 31, 1929, in Rochester, New York) is an American theoretical physicist and science essayist.
The joule (symbol: J) is a derived unit of energy in the International System of Units.
The Journal of Geophysical Research is a peer-reviewed scientific journal.
In physics, the kinetic energy of an object is the energy that it possesses due to its motion.
The kinetic theory describes a gas as a large number of submicroscopic particles (atoms or molecules), all of which are in constant rapid motion that has randomness arising from their many collisions with each other and with the walls of the container.
In 1929, physicist Oskar Klein obtained a surprising result by applying the Dirac equation to the familiar problem of electron scattering from a potential barrier.
Latin (Latin: lingua latīna) is a classical language belonging to the Italic branch of the Indo-European languages.
Lead is a chemical element with symbol Pb (from the Latin plumbum) and atomic number 82.
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.
Lise Meitner (7 November 1878 – 27 October 1968) was an Austrian-Swedish physicist who worked on radioactivity and nuclear physics.
This article includes a list of the different types of atomic- and sub-atomic particles found or hypothesized to exist in the whole of the universe categorized by type.
Lithium (from lit) is a chemical element with symbol Li and atomic number 3.
Luis Walter Alvarez (June 13, 1911 – September 1, 1988) was an American experimental physicist, inventor, and professor who was awarded the Nobel Prize in Physics in 1968.
Macmillan Publishers USA was the former name of a now mostly defunct American publishing company.
A magnet is a material or object that produces a magnetic field.
A magnetic field is a vector field that describes the magnetic influence of electrical currents and magnetized materials.
Mass is both a property of a physical body and a measure of its resistance to acceleration (a change in its state of motion) when a net force is applied.
The mass number (symbol A, from the German word Atomgewichte (atomic weight), also called atomic mass number or nucleon number, is the total number of protons and neutrons (together known as nucleons) in an atomic nucleus. It determines the atomic mass of atoms. Because protons and neutrons both are baryons, the mass number A is identical with the baryon number B as of the nucleus as of the whole atom or ion. The mass number is different for each different isotope of a chemical element. This is not the same as the atomic number (Z) which denotes the number of protons in a nucleus, and thus uniquely identifies an element. Hence, the difference between the mass number and the atomic number gives the number of neutrons (N) in a given nucleus:. The mass number is written either after the element name or as a superscript to the left of an element's symbol. For example, the most common isotope of carbon is carbon-12, or, which has 6 protons and 6 neutrons. The full isotope symbol would also have the atomic number (Z) as a subscript to the left of the element symbol directly below the mass number:. This is technically redundant, as each element is defined by its atomic number, so it is often omitted.
Mass spectrometry (MS) is an analytical technique that ionizes chemical species and sorts the ions based on their mass-to-charge ratio.
In physics, mass–energy equivalence states that anything having mass has an equivalent amount of energy and vice versa, with these fundamental quantities directly relating to one another by Albert Einstein's famous formula: E.
Maurice Goldhaber (April 18, 1911 – May 11, 2011) was an Austrian-born American physicist, who in 1957 (with Lee Grodzins and Andrew Sunyar) established that neutrinos have negative helicity.
In physics (in particular in statistical mechanics), the Maxwell–Boltzmann distribution is a particular probability distribution named after James Clerk Maxwell and Ludwig Boltzmann.
The mode of a set of data values is the value that appears most often.
A molecule is an electrically neutral group of two or more atoms held together by chemical bonds.
The muon (from the Greek letter mu (μ) used to represent it) is an elementary particle similar to the electron, with an electric charge of −1 e and a spin of 1/2, but with a much greater mass.
The natural logarithm of a number is its logarithm to the base of the mathematical constant ''e'', where e is an irrational and transcendental number approximately equal to.
Nature is a British multidisciplinary scientific journal, first published on 4 November 1869.
A neutrino (denoted by the Greek letter ν) is a fermion (an elementary particle with half-integer spin) that interacts only via the weak subatomic force and gravity.
Neutron 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.
Neutron activation analysis (NAA) is a nuclear process used for determining the concentrations of elements in a vast amount of materials.
A neutron bomb, officially defined as a type of enhanced radiation weapon (ERW), is a low yield thermonuclear weapon designed to maximize lethal neutron radiation in the immediate vicinity of the blast while minimizing the physical power of the blast itself.
Neutron capture is a nuclear reaction in which an atomic nucleus and one or more neutrons collide and merge to form a heavier nucleus.
Neutron capture nucleosynthesis describes two nucleosynthesis pathways: the r-process and the s-process, for rapid and slow neutron captures, respectively.
Neutron capture therapy (NCT) is a noninvasive therapeutic modality for treating locally invasive malignant tumors such as primary brain tumors and recurrent head and neck cancer.
Neutron diffraction or elastic neutron scattering is the application of neutron scattering to the determination of the atomic and/or magnetic structure of a material.
Neutron emission is a mode of radioactive decay in which one or more neutrons are ejected from a nucleus.
The neutron flux is a scalar quantity used in nuclear physics and nuclear reactor physics.
Neutron generators are neutron source devices which contain compact linear accelerators and that produce neutrons by fusing isotopes of hydrogen together.
The neutron magnetic moment is the intrinsic magnetic dipole moment of the neutron, symbol μn.
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.
The neutron number, symbol N, is the number of neutrons in a nuclide.
A neutron probe is a device used to measure the quantity of water present in soil.
Neutron radiation is a form of ionizing radiation that presents as free neutrons.
A neutron reflector is any material that reflects neutrons.
A neutron research facility is most commonly a big laboratory operating a large-scale neutron source that provides thermal neutrons to a suite of research instruments.
Neutron scattering, the irregular dispersal of free neutrons by matter, can refer to either the naturally occurring physical process itself or to the man-made experimental techniques that use the natural process for investigating materials.
A neutron source is any device that emits neutrons, irrespective of the mechanism used to produce the neutrons.
A neutron star is the collapsed core of a large star which before collapse had a total of between 10 and 29 solar masses.
A neutron supermirror is a highly polished surface used in connection with neutron beams.
The neutron detection temperature, also called the neutron energy, indicates a free neutron's kinetic energy, usually given in electron volts.
Neutron tomography is a form of computed tomography involving the production of three-dimensional images by the detection of the absorbance of neutrons produced by a neutron source.
Neutron transport is the study of the motions and interactions of neutrons with materials.
A neutron-velocity selector is a device that allows neutrons of defined velocity to pass while absorbing all other neutrons, to produce a monochromatic neutron beam.
The neutron–proton ratio (N/Z ratio or nuclear ratio) of an atomic nucleus is the ratio of its number of neutrons to its number of protons.
Neutronium (sometimes shortened to neutrium, also referred to as neutrite) is a hypothetical substance composed purely of neutrons.
The Nobel Foundation (Nobelstiftelsen) is a private institution founded on 29 June 1900 to manage the finances and administration of the Nobel Prizes.
The Nobel Prize in Chemistry (Nobelpriset i kemi) is awarded annually by the Royal Swedish Academy of Sciences to scientists in the various fields of chemistry.
The Nobel Prize in Physics (Nobelpriset i fysik) is a yearly award given by the Royal Swedish Academy of Sciences for those who conferred the most outstanding contributions for mankind in the field of physics.
A nuclear chain reaction occurs when one single nuclear reaction causes an average of one or more subsequent nuclear reactions, thus leading to the possibility of a self-propagating series of these reactions.
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).
The nuclear force (or nucleon–nucleon interaction or residual strong force) is a force that acts between the protons and neutrons of atoms.
Nuclear fuel is a substance that is used in nuclear power stations to produce heat to power turbines.
In nuclear physics, nuclear fusion is a reaction in which two or more atomic nuclei come close enough to form one or more different atomic nuclei and subatomic particles (neutrons or protons).
The nuclear magneton (symbol μN), is a physical constant of magnetic moment, defined in SI units by: and in Gaussian CGS units by: where: In SI units, its value is approximately: In Gaussian CGS units, its value can be given in convenient units as The nuclear magneton is the natural unit for expressing magnetic dipole moments of heavy particles such as nucleons and atomic nuclei.
Nuclear physics is the field of physics that studies atomic nuclei and their constituents and interactions.
Nuclear proliferation is the spread of nuclear weapons, fissionable material, and weapons-applicable nuclear technology and information to nations not recognized as "Nuclear Weapon States" by the Treaty on the Non-Proliferation of Nuclear Weapons, commonly known as the Non-Proliferation Treaty or NPT.
In nuclear physics and nuclear chemistry, a nuclear reaction is semantically considered to be the process in which two nuclei, or else a nucleus of an atom and a subatomic particle (such as a proton, neutron, or high energy electron) from outside the atom, collide to produce one or more nuclides that are different from the nuclide(s) that began the process.
A nuclear reactor, formerly known as an atomic pile, is a device used to initiate and control a self-sustained nuclear chain reaction.
In nuclear physics and nuclear chemistry, the nuclear shell model is a model of the atomic nucleus which uses the Pauli exclusion principle to describe the structure of the nucleus in terms of energy levels.
Nuclear transmutation is the conversion of one chemical element or an isotope into another chemical element.
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.
In chemistry and physics, a nucleon is either a proton or a neutron, considered in its role as a component of an atomic nucleus.
Nucleosynthesis is the process that creates new atomic nuclei from pre-existing nucleons, primarily protons and neutrons.
A nuclide (from nucleus, also known as nuclear species) is an atomic species characterized by the specific constitution of its nucleus, i.e., by its number of protons Z, its number of neutrons N, and its nuclear energy state.
Nuovo Cimento is a series of peer-reviewed scientific journals of physics.
Oscar Wallace Greenberg (born February 18, 1932) is an American physicist and professor at University of Maryland College of Computer, Mathematical, and Natural Sciences.
Oskar Benjamin Klein (15 September 1894 – 5 February 1977) was a Swedish theoretical physicist.
Otto Hahn, (8 March 1879 – 28 July 1968) was a German chemist and pioneer in the fields of radioactivity and radiochemistry.
Oxford University Press (OUP) is the largest university press in the world, and the second oldest after Cambridge University Press.
Paraffin wax is a white or colourless soft solid, derived from petroleum, coal or oil shale, that consists of a mixture of hydrocarbon molecules containing between twenty and forty carbon atoms.
A particle accelerator is a machine that uses electromagnetic fields to propel charged particles to nearly light speed and to contain them in well-defined beams.
The Paul Scherrer Institute (PSI) is a multi-disciplinary research institute which belongs to the Swiss Federal Institutes of Technology Domain covering also ETH Zurich and EPFL.
The Pauli exclusion principle is the quantum mechanical principle which states that two or more identical fermions (particles with half-integer spin) cannot occupy the same quantum state within a quantum system simultaneously.
Photodisintegration (also called phototransmutation) is a nuclear process in which an atomic nucleus absorbs a high-energy gamma ray, enters an excited state, and immediately decays by emitting a subatomic particle.
The photon is a type of elementary particle, the quantum of the electromagnetic field including electromagnetic radiation such as light, and the force carrier for the electromagnetic force (even when static via virtual particles).
Phys.org is a science, research and technology news aggregator where much of the content is republished directly from press releases and news agencies-in a practice known as churnalism.
Physical Review is an American peer-reviewed scientific journal established in 1893 by Edward Nichols.
Physical Review Letters (PRL), established in 1958, is a peer-reviewed, scientific journal that is published 52 times per year by the American Physical Society.
Physics beyond the Standard Model (BSM) refers to the theoretical developments needed to explain the deficiencies of the Standard Model, such as the origin of mass, the strong CP problem, neutrino oscillations, matter–antimatter asymmetry, and the nature of dark matter and dark energy.
The Planck constant (denoted, also called Planck's constant) is a physical constant that is the quantum of action, central in quantum mechanics.
Plutonium-239 is an isotope of plutonium.
Polonium is a chemical element with symbol Po and atomic number 84.
The positron or antielectron is the antiparticle or the antimatter counterpart of the electron.
Positron emission or beta plus decay (β+ decay) is a subtype of radioactive decay called beta decay, in which a proton inside a radionuclide nucleus is converted into a neutron while releasing a positron and an electron neutrino (νe).
In physics, potential energy is the energy possessed by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors.
Proceedings of the Royal Society is the parent title of two scientific journals published by the Royal Society.
Prompt-gamma neutron activation analysis (PGAA) is a very widely applicable technique for determining the presence and amount of many elements simultaneously in samples ranging in size from micrograms to many grams.
Quantum mechanics (QM; also known as quantum physics, quantum theory, the wave mechanical model, or matrix mechanics), including quantum field theory, is a fundamental theory in physics which describes nature at the smallest scales of energy levels of atoms and subatomic particles.
Quantum numbers describe values of conserved quantities in the dynamics of a quantum system.
A quark is a type of elementary particle and a fundamental constituent of matter.
In particle physics, the quark model is a classification scheme for hadrons in terms of their valence quarks—the quarks and antiquarks which give rise to the quantum numbers of the hadrons.
The rapid neutron-capture process, or so-called r-process, is a set of nuclear reactions that in nuclear astrophysics is responsible for the creation (nucleosynthesis) of approximately half the abundances of the atomic nuclei heavier than iron, usually synthesizing the entire abundance of the two most neutron-rich stable isotopes of each heavy element.
In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium.
Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is therapy using ionizing radiation, generally as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator.
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.
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is an atom that has excess nuclear energy, making it unstable.
In classical geometry, a radius of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length.
Reactor-grade plutonium/RGPu is the isotopic grade of plutonium that is found in spent nuclear fuel after the primary fuel, that of Uranium-235 that a nuclear power reactor uses, has (burnt up/burnup).
Research reactors are nuclear reactors that serve primarily as a neutron source.
In physics, resonance is a phenomenon in which a vibrating system or external force drives another system to oscillate with greater amplitude at specific frequencies.
The slow neutron-capture process or s-process is a series of reactions in nuclear astrophysics that occur in stars, particularly AGB stars.
, usually cited as Sin-Itiro Tomonaga in English, was a Japanese physicist, influential in the development of quantum electrodynamics, work for which he was jointly awarded the Nobel Prize in Physics in 1965 along with Richard Feynman and Julian Schwinger.
The sievert (symbol: SvNot be confused with the sverdrup or the svedberg, two non-SI units that sometimes use the same symbol.) is a derived unit of ionizing radiation dose in the International System of Units (SI) and is a measure of the health effect of low levels of ionizing radiation on the human body.
Spallation is a process in which fragments of material (spall) are ejected from a body due to impact or stress.
The Spallation Neutron Source (SNS) is an accelerator-based neutron source facility that provides the most intense pulsed neutron beams in the world for scientific research and industrial development.
In physics, special relativity (SR, also known as the special theory of relativity or STR) is the generally accepted and experimentally well-confirmed physical theory regarding the relationship between space and time.
The speed of light in vacuum, commonly denoted, is a universal physical constant important in many areas of physics.
In quantum mechanics and particle physics, spin is an intrinsic form of angular momentum carried by elementary particles, composite particles (hadrons), and atomic nuclei.
In quantum mechanics, spin is an intrinsic property of all elementary particles.
Spontaneous fission (SF) is a form of radioactive decay that is found only in very heavy chemical elements.
Springer Science+Business Media or Springer, part of Springer Nature since 2015, is a global publishing company that publishes books, e-books and peer-reviewed journals in science, humanities, technical and medical (STM) publishing.
Stable nuclides are nuclides that are not radioactive and so (unlike radionuclides) do not spontaneously undergo radioactive decay.
In statistics, the standard deviation (SD, also represented by the Greek letter sigma σ or the Latin letter s) is a measure that is used to quantify the amount of variation or dispersion of a set of data values.
The Standard Model of particle physics is the theory describing three of the four known fundamental forces (the electromagnetic, weak, and strong interactions, and not including the gravitational force) in the universe, as well as classifying all known elementary particles.
A star is type of astronomical object consisting of a luminous spheroid of plasma held together by its own gravity.
Startup neutron source is a neutron source used for stable and reliable initiation of nuclear chain reaction in nuclear reactors, when they are loaded with fresh nuclear fuel, whose neutron flux from spontaneous fission is insufficient for a reliable startup, or after prolonged shutdown periods.
The Stern–Gerlach experiment demonstrated that the spatial orientation of angular momentum is quantized.
In particle physics, the strong interaction is the mechanism responsible for the strong nuclear force (also called the strong force or nuclear strong force), and is one of the four known fundamental interactions, with the others being electromagnetism, the weak interaction, and gravitation.
SU(6) is a grand unified theory which includes the Georgi–Glashow SU(5) gauge group.
In the physical sciences, subatomic particles are particles much smaller than atoms.
Surface exposure dating is a collection of geochronological techniques for estimating the length of time that a rock has been exposed at or near Earth's surface.
In relation to the chemical elements, a symbol is a code for a chemical element.
A synonym is a word or phrase that means exactly or nearly the same as another word or phrase in the same language.
A table of nuclides or chart of nuclides is a two-dimensional graph in which one axis represents the number of neutrons and the other represents the number of protons in an atomic nucleus.
The tesla (symbol T) is a derived unit of magnetic flux density (informally, magnetic field strength) in the International System of Units.
A tetraneutron is a hypothetical stable cluster of four neutrons.
The Science of Nature, formerly Naturwissenschaften, is a monthly peer-reviewed scientific journal published by Springer Science+Business Media covering all aspects of the natural sciences relating to questions of biological significance.
A thermal-neutron reactor is a nuclear reactor that uses slow or thermal neutrons.
A thermonuclear weapon is a second-generation nuclear weapon design using a secondary nuclear fusion stage consisting of implosion tamper, fusion fuel, and spark plug which is bombarded by the energy released by the detonation of a primary fission bomb within, compressing the fuel material (tritium, deuterium or lithium deuteride) and causing a fusion reaction.
The thorium fuel cycle is a nuclear fuel cycle that uses an isotope of thorium,, as the fertile material.
Tin is a chemical element with the symbol Sn (from stannum) and atomic number 50.
A tokamak (Токамáк) is a device that uses a powerful magnetic field to confine a hot plasma in the shape of a torus.
In quantum mechanics, the total angular momentum quantum number parameterises the total angular momentum of a given particle, by combining its orbital angular momentum and its intrinsic angular momentum (i.e., its spin).
A system is said to be in a transient state when a process variable or variables have been changed and the system has not yet reached a steady state.The time taken for the circuit to change from one steady state to another steady state is called the transient time. Transient analysis KVL and KCL to circuits containing energy storage elements results in differential.
Trinity was the code name of the first detonation of a nuclear weapon.
Tritium (or; symbol or, also known as hydrogen-3) is a radioactive isotope of hydrogen.
Ultracold neutrons (UCN) are free neutrons which can be stored in traps made from certain materials.
In quantum mechanics, the uncertainty principle (also known as Heisenberg's uncertainty principle) is any of a variety of mathematical inequalities asserting a fundamental limit to the precision with which certain pairs of physical properties of a particle, known as complementary variables, such as position x and momentum p, can be known.
The unified atomic mass unit or dalton (symbol: u, or Da) is a standard unit of mass that quantifies mass on an atomic or molecular scale (atomic mass).
The University of Sussex is a public research university in Falmer, Sussex, England.
, abbreviated as or UTokyo, is a public research university located in Bunkyo, Tokyo, Japan.
The up quark or u quark (symbol: u) is the lightest of all quarks, a type of elementary particle, and a major constituent of matter.
Uranium-233 is a fissile isotope of uranium that is bred from thorium-232 as part of the thorium fuel cycle.
Uranium-235 (235U) is an isotope of uranium making up about 0.72% of natural uranium.
The W and Z bosons are together known as the weak or more generally as the intermediate vector bosons. These elementary particles mediate the weak interaction; the respective symbols are,, and.
Walther Wilhelm Georg Bothe (8 January 1891 – 8 February 1957) was a German nuclear physicist, who shared the Nobel Prize in Physics in 1954 with Max Born.
Water is a transparent, tasteless, odorless, and nearly colorless chemical substance that is the main constituent of Earth's streams, lakes, and oceans, and the fluids of most living organisms.
A wave function in quantum physics is a mathematical description of the quantum state of an isolated quantum system.
In particle physics, the weak interaction (the weak force or weak nuclear force) is the mechanism of interaction between sub-atomic particles that causes radioactive decay and thus plays an essential role in nuclear fission.
Werner Karl Heisenberg (5 December 1901 – 1 February 1976) was a German theoretical physicist and one of the key pioneers of quantum mechanics.
X-rays make up X-radiation, a form of electromagnetic radiation.
Zeitschrift für Physik (English: Journal for physics) is a defunct series of German peer-reviewed German scientific journal of physics established in 1920 by Springer Berlin Heidelberg.