alpha particle — (Physics & Chem.) a particle emitted at high velocity from certain radioactive substances. It is identical to the helium nucleus, consisting of two protons and two neutrons. Rays of such particles are called {alpha rays}. [Webster 1913 Suppl.… … The Collaborative International Dictionary of English
alpha decay — Physics. a radioactive process in which an alpha particle is emitted from the nucleus of an atom, decreasing its atomic number by two. [1935 40] * * * Type of radioactive disintegration (see radioactivity) in which some unstable atomic nuclei… … Universalium
alpha particle — noun a positively charged particle that is the nucleus of the helium atom; emitted from natural or radioactive isotopes • Hypernyms: ↑particle, ↑subatomic particle * * * ˈalpha particle [alpha particle] noun ( … Useful english dictionary
Alpha process — The Alpha process (or alpha reactions) is one of two classes of nuclear fusion reactions by which stars convert helium into heavier elements, the other being the triple alpha process.While the triple alpha process only requires helium, once some… … Wikipedia
Alpha particle — Alpha particles (named after and denoted by the first letter in the Greek alphabet, α) consist of two protons and two neutrons bound together into a particle identical to a helium nucleus; hence, it can be written as He2+ or 42He2+. They are a… … Wikipedia
Particle radiation — is the radiation of energy by means of fast moving subatomic particles. Particle radiation is referred to as a particle beam if the particles are all moving in the same direction, similar to a light beam.Due to the wave particle duality, all… … Wikipedia
Alpha — may refer to:The Greek letter alphaAlpha (letter), a letter in the Greek alphabet. α may be used as the symbol for: *Alpha channel, describing transparency and opacity in computer graphics *Angle of attack in aerodynamics *Common base current… … Wikipedia
particle — 1 Particle, bit, mite, smidgen, whit, atom, iota, jot, tittle all mean a very small or insignificant piece or part. Particle is used in reference not only to substances which are actually divisible but to such things as a quality, a state, or a… … New Dictionary of Synonyms
Alpha (letter) — Alpha (uppercase Α, lowercase α; el. Αλφα) is the first letter of the Greek alphabet. In the system of Greek numerals it has a value of 1. It was derived from the Phoenician letter Aleph .In both Classical Greek and Modern Greek, alpha represents … Wikipedia
alpha particle — n. a positively charged particle given off by certain radioactive substances: it consists of two protons and two neutrons (a helium nucleus), and is converted into an atom of helium by the acquisition of two electrons … English World dictionary
