gamma ray

American  

noun

Physics.

1. a photon of penetrating electromagnetic radiation gamma radiation emitted from an atomic nucleus.

2. a photon emitted by an electron as a result of internal conversion.

3. electromagnetic radiation with wavelengths shorter than approximately one tenth of a nanometer.

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gamma ray Scientific  

1. A stream of high-energy electromagnetic radiation given off by an atomic nucleus undergoing radioactive decay. Because the wavelengths of gamma rays are shorter than those of x-rays, gamma rays have greater energy and penetrating power than x-rays. Gamma rays are emitted by pulsars, quasars, and radio galaxies but cannot penetrate the Earth's atmosphere.

2. See more at radioactive decay

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Etymology

Origin of gamma ray

First recorded in 1900–05

Example Sentences

Totani explains that the gamma ray pattern cannot be easily matched to other known sources or more common astrophysical processes.

From Science Daily • Nov. 29, 2025

Further support could come from finding the same gamma ray signature in other regions rich in dark matter.

From Science Daily • Nov. 29, 2025

Because of this, he views the data as a strong candidate for long-sought gamma ray emission from dark matter.

From Science Daily • Nov. 29, 2025

The gamma ray burst lasted seven minutes and was so powerful that it was off the scale, overwhelming the instruments that detected them.

From BBC • Apr. 12, 2024

And to observe these few coming from the distance of Pluto would require a larger gamma ray detector than any that have been constructed so far.

From "A Brief History of Time: And Other Essays" by Stephen Hawking