annihilation radiation

American  

noun

Physics.

1. electromagnetic radiation produced by the coalescence and mutual annihilation of an atomic particle and its antiparticle, generally a positron and an electron, each pair forming two photons having a minimum energy of 0.5 million electron volts each.

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Etymology

Origin of annihilation radiation

First recorded in 1960–65

Example Sentences

Then they tracked the resulting annihilation radiation at the farthest edges of their experiment, using two photomultiplier tubes, anthracene crystals and a scintillation counter as a gamma-ray detector.

From Scientific American