alpha particle

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alpha particle

n.
A positively charged subatomic particle, composed of two protons and two neutrons, identical with the nucleus of the helium isotope He-4.

alpha particle

n
(General Physics) a helium-4 nucleus, containing two neutrons and two protons, emitted during some radioactive transformations

al′pha par`ticle


n.
a positively charged particle consisting of two protons and two neutrons, emitted in radioactive decay or nuclear fission; the nucleus of a helium atom.
[1900–05]

alpha particle

A positively charged particle that consists of two protons and two neutrons bound together. It is emitted by the nucleus of some elements undergoing radioactive decay and is identical to the nucleus of a helium atom. Alpha particles are the slowest and least penetrating forms of nuclear radiation. ♦ The process by which a radioactive element emits an alpha particle is called alpha decay. Alpha decay results in the atomic number of the atom being decreased by two and the mass number being decreased by four. See more at radiation, radioactive decay.

alpha particle

A helium nucleus that has a positive electric charge.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.alpha particle - a positively charged particle that is the nucleus of the helium atomalpha particle - a positively charged particle that is the nucleus of the helium atom; emitted from natural or radioactive isotopes
subatomic particle, particle - a body having finite mass and internal structure but negligible dimensions
References in periodicals archive ?
Polonium has few applications, and those are related to its radioactivity: heaters in space probes; antistatic devices; and sources of neutrons and alpha particles.
Actinium-225 gives off high-energy alpha particles as it decays, which kill cancer cells and as actinium-225 decays it produces a series of daughter atoms, each of which gives off its own alpha particle, increasing the chances that the cancer cell will be destroyed.
It uses the interaction of alpha particles with the nitrogen in the air to form fluorescence, so we measure alpha radiation using light.
The draft guidance on the drug - which homes in on tumours that have metastasised, or spread, to the bones and blasts them with alpha particles - has been hailed by charities an "important victory" for some patients.
Most radioactive sources produce gamma rays and alpha particles, which are of various energies and intensities.
They cover machine architecture and objectives; a magnetohydrodynamic description of the equilibrium and heating of the thermal plasma; Alfven cavity modes, fast ions, alpha particles, and diagnostic neutral beams; turbulent transport from the temperature gradients; operational regimes and their properties; transport barriers and edged localized modes control; steady-state operation; plasma diagnostics; plasma facing components and plasma-wall interaction physics; and the broader approach and tritium breeding blankets.
In order to investigate a particular material, the device bombards its surface with alpha particles and X-rays.
It detects radiation such as alpha particles, beta particles and gamma rays using the ionization produced in a Geiger--ME-ller tube, which gives its name to the instrument.
Alpha particles consist of two protons and two neutrons.
As it can be seen in the radon decay chain, number of alpha particles emitted in this chain is high and given that alpha particle considered as one of the most dangerous particles resulted from decays so this gas can be considered as one of the dangerous radioactive gases.
The alpha particles further heat the fuel, increasing the rate of fusion reactions, thus producing more alpha particles.