Crossword clues for positron
Longman Dictionary of Contemporary English
The Collaborative International Dictionary
antipartticle \an`ti*part"ti*cle\ ([a^]n`t[i^]*[aum]r"t[i^]*k'l), n. (Physics) A fundamental particle which has the same mass as one of the common fundamental particles, but which has an opposite charge, and for which certain other of the properties (e. g. baryon number, strangeness) may be opposite to that of the normal particle. The antiparticle to an electron is called a positron; the antiparticle to a proton is called an antiproton; the antiparticle to a neutron is called an antineutron. When a particle and its corresponding antiparticle collide, they typically annihilate each other with the production of large quantities of energy, usually in the form of radiation. The interaction of a proton and antiproton cause annihilation with production of mesons.
Douglas Harper's Etymology Dictionary
1933, coined from posi(tive) (elec)tron.
Wiktionary
n. (context particle English) The antimatter equivalent of an electron, having the same mass but a positive charge
WordNet
n. an elementary particle with positive charge; interaction of a positron and an electron results in annihilation [syn: antielectron]
Wikipedia
The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. The positron has an electric charge of +1 e, a spin of 1/2, and has the same mass as an electron. When a low-energy positron collides with a low-energy electron, annihilation occurs, resulting in the production of two or more gamma ray photons (see electron–positron annihilation).
Positrons may be generated by positron emission radioactive decay (through weak interactions), or by pair production from a sufficiently energetic photon which is interacting with an atom in a material.
A positron is an elementary particle of antimatter.
Positron may also refer to:
- "Positron", a 1993 trance track by Cygnus X
- Positron bicycle shifting system from Shimano
- Positron (City of Heroes), the comic/video game character
- Positron emission, the radioactive decay
- Positronic brain, the fictional device conceived by Isaac Asimov
- Positron Public Safety Systems, a manufacturer of Enhanced 9-1-1 Telephone Systems
- Positron! Records, the Chicago based independent record label
- Positron (video game), the 1983 video game published by Micro Power
- Positron Corporation, an American nuclear medicine healthcare company
Positron is a video game which was published for the BBC Micro and Acorn Electron computers by Micro Power in 1983. It was developed on a pre-release Electron and was one of the few games (other than those produced by Acornsoft) available for the machine on its launch.
Usage examples of "positron".
FDG Positron Emission Tomography and other neuroimaging devices for suspected dementia.
When a pion, this subatomic particle, decays it becomes an electron and a positron, and they must be in antiparallel spin states so as not to violate conservation of spin angular momentum.
To distinguish the ensuing trajectory of the photon from the previous trajectories of the electron and positron, we follow a traditional physics convention and draw it with a wiggly line.
Within it, quadrillions of quadrillions of positrons came into being and vanished in millionths of a second.
The positronic cannon of the DIED ships were sometimes called Auger guns because of their use of a variation on the Auger effect by which suitably excited atoms emit, instead of electromagnetic radiation or an electron, an antielectron, or positron.
Electrons and positrons, neutrinos and antineutrinos, photons with billion-light-year wavelengths all swirled through the cosmos.
FDG Positron Emission Tomography and other neuroimaging devices for suspected dementia.
And when a proton annihilates an antiproton, it produces a pi-zero meson one-third of the time, and a charged pion, a muon, and a neutrino two-thirds of the time, after which the pions and neutrons promptly break down to electrons and positrons, photons and neutrinos.
Alpha particles should shove them out of the way with equal ease, and if positrons make up the brain paths, shoving them away disrupts the brain paths and inactivates the robots.
This depends on injecting very short-lived and presumably non-hazardous radioisotopes into the bloodstream and then detecting, by means of their emission of positrons, where they are in the brain at times up to half an hour or so after injection.
The universe was a mass of electrons, positrons, neutrons, and photons.
Since electrons and positrons, and all the other particles for that matter, are only harmonics of closed strings, the numbers that were created are essentially random.
The neutrons absorbed the positrons to become protons, and the electrons were drawn off.
He could try other more energetic transmissions, bursts of positrons, muons, gamma rays, or antiprotons that might attract attention to the Bridgehead.
The positrons were channeled by tuned fields and directed at a confined, negative space-charge to produce the sustained annihilations that the process demanded.