alpha particle

Definitions

  • WordNet 3.6
    • n alpha particle a positively charged particle that is the nucleus of the helium atom; emitted from natural or radioactive isotopes
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Webster's Revised Unabridged Dictionary
    • 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.
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Usage

In literature:

We may safely regard such helium as formed by the accumulation of alpha-ray particles given out by successive radio-active changes.
"Darwin and Modern Science" by A.C. Seward and Others
But thorium mostly gives off the kind of radiation known as alpha particles.
"Rip Foster in Ride the Gray Planet" by Harold Leland Goodwin
Those alpha particles are helium atoms.
"The Breath of Life" by John Burroughs
Each moment of {alpha} will intersect a point-track in one and only one event-particle.
"The Concept of Nature" by Alfred North Whitehead
Lastly, we have the production of helium from the alpha particles.
"A Brief Account of Radio-activity" by Francis Preston Venable
Deuterons or alpha particles are obtained in a similar fashion using deuterium or helium gas in place of hydrogen.
"LRL Accelerators" by Lawrence Radiation Laboratory
Each flash is due to an alpha particle striking the screen.
"Physics" by Willis Eugene Tower
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In news:

Researchers used the Curiosity rover's mast camera, on September 7, to take a photo of the Alpha Particle X-Ray Spectrometer.
Algeta is evaluating the potential utility of alpha-particle emitting elements in the treatment of cancer.
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In science:

In this chapter we concentrate ourselves mainly on the effects produced by proton irradiation in highly oriented pyrolitic graphite (HOPG). Effects of irradiation with alpha particles will be discussed shortly in section 3.1.3.
Induced Magnetic Order by Ion Irradiation of Carbon-Based Structures
The total amount of protons or alpha particles that were implanted in the sample or travelled through the sample. – (2) The input energy.
Induced Magnetic Order by Ion Irradiation of Carbon-Based Structures
Alpha-particle partial widths are calculated using the α-particle branching ratios adopted by Ref. , except for the two first resonances.
Charged-Particle Thermonuclear Reaction Rates: II. Tables and Graphs of Reaction Rates and Probability Density Functions
Production of alpha-particles is characterized by a low-energy threshold, typically ǫth ∼ 7 − 10 MeV, but it is suppressed by smaller cross-sections.
Analytic calculations of the spectra of ultra high energy cosmic ray nuclei. II. The general case of background radiation
The different curves correspond to photo-disintegration with different multiplicity of the emitted protons: the second curve from above (green) for multiplicity i = 1, the third curve for i = 2 (blue), the lowest curve for largest multiplicity i allowed by available experimental data, with alpha-particles included.
Analytic calculations of the spectra of ultra high energy cosmic ray nuclei. II. The general case of background radiation
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