pos·​i·​tron | \ ˈpä-zə-ˌträn How to pronounce positron (audio) \

Definition of positron

: a positively charged particle having the same mass and magnitude of charge as the electron and constituting the antiparticle of the electron

called also antielectron

Examples of positron in a Sentence

Recent Examples on the Web

These radiotracers decay via positron emission, creating back-to-back gamma rays that are simultaneously detected by a PET scanner. Julie Grisham, Scientific American, "Faster, clearer PET images offer new views on disease," 9 July 2019 The first stage will see the FCC collide electrons with positrons, the antimatter electron counterpart. Avery Thompson, Popular Mechanics, "Scientists Are Planning a New Particle Collider That Absolutely Dwarfs the LHC," 16 Jan. 2019 Electrons can then be added to create an electron-positron plasma. Chris Lee, Ars Technica, "Technical tour-de-force traps positrons," 11 Dec. 2018 When excited, an atom can absorb a third photon, which strips away its positron entirely. Adrian Cho, Science | AAAS, "Atoms and antiatoms haven’t crashed Albert Einstein’s theory of relativity—yet," 4 Apr. 2018 His design would measure the spectrum and shape of the initial Cherenkov flash and thus the energy of the progenitor antineutrinos from the positrons. Jesse Emspak, Scientific American, "Detection of Ghostly Particles Could Unmask Illicit Nuclear Weapons," 1 May 2017 An electron and its antiparticle, a positron, have identical properties except for charge, but the charge of the Majorana particle would be zero. Neil Savage, Scientific American, "What Are the Limits of Manipulating Nature?," 8 May 2018 When this collision occurs, the proton transforms into a neutron and ejects a positron, the antimatter version of an electron. Kenneth Chang, New York Times, "How to Spot a Nuclear Bomb Program? Look for Ghostly Particles," 27 Mar. 2018 But in reality, antimatter is really no different than regular matter, except that antimatter atoms have positrons instead of electrons and antiprotons instead of protons. Sophie Weiner, Popular Mechanics, "How To Make and Trap Antimatter," 1 Apr. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'positron.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of positron

1933, in the meaning defined above

History and Etymology for positron

positive + -tron (as in electron)

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Last Updated

16 Jul 2019

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Time Traveler for positron

The first known use of positron was in 1933

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English Language Learners Definition of positron

physics : a very small particle of matter that has a positive charge of electricity and that travels around the nucleus of an atom


pos·​i·​tron | \ ˈpäz-ə-ˌträn How to pronounce positron (audio) \

Medical Definition of positron

: a positively charged particle having the same mass and magnitude of charge as the electron and constituting the antiparticle of the electron

called also positive electron

More from Merriam-Webster on positron

Rhyming Dictionary: Words that rhyme with positron

Britannica.com: Encyclopedia article about positron

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something desired as essential

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