| Composition | Elementary particle |
|---|---|
| Family | Fermion |
| Group | Lepton |
| Generation | First |
| Interaction | Gravity, Electromagnetic, Weak |
| Antiparticle | Electron |
| Theorized | Paul Dirac, 1928 |
| Discovered | Carl D. Anderson, 1932 |
| Symbol | β+, e+ |
| Mass | 9. In Particle physics, an elementary particle or fundamental particle is a particle not known to have substructure that is it is not known to be made In Particle physics, fermions are particles which obey Fermi-Dirac statistics; they are named after Enrico Fermi. Leptons are a family of fundamental Subatomic particles comprising the Electron, the Muon, and the Tauon (or tau particle as well as their In Particle physics, a generation is a division of the Elementary particles Between generations particles differ only by their Mass. In Physics, a fundamental interaction or fundamental force is a mechanism by which particles interact with each other and which cannot be explained in terms Gravitation is a natural Phenomenon by which objects with Mass attract one another In Physics, the electromagnetic force is the force that the Electromagnetic field exerts on electrically charged particles The weak interaction (often called the weak force or sometimes the weak nuclear force) is one of the four Fundamental interactions of nature to most kinds of particles, there is an associated antiparticle with the same Mass and opposite Electric charge. The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J Carl David Anderson ( 3 September 1905 &ndash 11 January 1991) was an American Physicist. 1093826(16)×10−31 kg[1] 0. The unified atomic mass unit ( u) or Dalton ( Da) or sometimes universal mass unit, is an unit of Mass used to express 510998917(44) MeV/c2[2] |
| Electric charge | 1. The elementary charge, usually denoted e, is the Electric charge carried by a single Proton, or equivalently the negative of the electric charge carried 602176462(63)×10−19 C[1] |
| Spin | ½ |
The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. In Quantum mechanics, spin is a fundamental property of atomic nuclei, Hadrons and Elementary particles For particles with non-zero spin to most kinds of particles, there is an associated antiparticle with the same Mass and opposite Electric charge. In Particle physics and Quantum chemistry, antimatter is the extension of the concept of the Antiparticle to Matter, where antimatter is composed The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J The positron has an electric charge of +1, a spin of 1/2, and the same mass as an electron. Electric charge is a fundamental conserved property of some Subatomic particles which determines their Electromagnetic interaction. In Quantum mechanics, spin is a fundamental property of atomic nuclei, Hadrons and Elementary particles For particles with non-zero spin When a low-energy positron collides with a low-energy electron, annihilation occurs, resulting in the production of two gamma ray photons (see electron-positron annihilation). Annihilation is defined as "total destruction" or "complete obliteration" of an object having its root in the Latin nihil (nothing Gamma rays (denoted as &gamma) are a form of Electromagnetic radiation or light emission of frequencies produced by sub-atomic particle interactions In Physics, the photon is the Elementary particle responsible for electromagnetic phenomena Electron-positron annihilation occurs when an Electron and a Positron (the electron's anti-particle) collide The first scientist deemed to have captured positrons through electron-positron annihilation was Chung-Yao Chao, a graduate student at Caltech in 1930, though he did not realize what they were at that time. Chung-Yao Chao ( ( 27 June 1902 – 28 May 1998) was a Chinese physicist The California Institute of Technology (commonly referred to as Caltech) is a private, Coeducational research university located in Pasadena
Positrons may be generated by positron emission radioactive decay (a weak interaction), or by pair production from a sufficiently energetic photon. Positron emission is a type of Beta decay, sometimes referred to as " beta plus " (&beta+ The weak interaction (often called the weak force or sometimes the weak nuclear force) is one of the four Fundamental interactions of nature See also Electron-positron annihilation Meitner–Hupfeld effect Pair instability supernova In Physics, the photon is the Elementary particle responsible for electromagnetic phenomena
The existence of positrons was first postulated in 1928 by Paul Dirac as a consequence of the Dirac equation. In Physics, the Dirac equation is a relativistic quantum mechanical wave equation formulated by British physicist Paul Dirac in 1928 and provides In 1932, positrons were discovered by Carl D. Anderson, who gave the positron its name. Carl David Anderson ( 3 September 1905 &ndash 11 January 1991) was an American Physicist. [3] The positron was the first evidence of antimatter and was discovered by passing cosmic rays through a cloud chamber and a lead plate surrounded by a magnet to distinguish the particles by bending differently charged particles in different directions. In Particle physics and Quantum chemistry, antimatter is the extension of the concept of the Antiparticle to Matter, where antimatter is composed For the 1962 Bruce Conner film see Cosmic Ray (film Cosmic rays are energetic particles originating from space that impinge on The cloud chamber, also known as the Wilson chamber, is used for detecting particles of Ionizing radiation.
Today, positrons, created through the decay of a radioactive tracer, are detected in positron emission tomography (PET) scanners used in hospitals and in accelerator physics laboratories used in electron-positron collider experiments. Positron emission tomography ( PET) is a Nuclear medicine imaging technique which produces a three-dimensional image or map of functional processes in the In the case of PET scanners, positrons provide a mechanism to show areas of activity within the human brain. In addition to the two above-mentioned applications of positrons in medicine and fundamental physics, an experimental tool called positron annihilation spectroscopy (sometimes referred to as PAS) is used in materials research. Positron annihilation spectroscopy (PAS or Positron lifetime spectroscopy is a non-destructive Spectroscopy technique to study voids and defects in solids
See also
References
- ^ a b c positron - Britannica Online Encyclopedia
- ^ Electron Mass - from Eric Weisstein's World of Physics
- ^ Anderson, Carl D. Beta particles are high-energy high-speed Electrons or Positrons emitted by certain types of Radioactive nuclei such as Potassium -40 Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. This is a list of the different types of particles known and hypothesized Positron emission tomography ( PET) is a Nuclear medicine imaging technique which produces a three-dimensional image or map of functional processes in the A positronic brain is a fictional technological device originally conceived by Science fiction writer Isaac Asimov. (1933). "The Positive Electron". Physical Review 43 (6): 491-494. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
External links
- What is a Positron? (from the Frequently Asked Questions :: Center for Antimatter-Matter Studies)
- Positron information search at SLAC
- Positron Annihilation as a method of experimental physics used in materials research.
Dictionary
positron
-noun
- (physics) The antimatter equivalent of an electron, having the same mass but a positive charge
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic