A subatomic particle of mass and charge equal to the electron but of opposite ( i.e., positive) charge. SYN: positive electron.
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pos·i·tron 'päz-ə-.trän n 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
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n.
an electrically charged particle released in some radioactive decays, notably fluorine-18 or nitrogen-13, that has the same mass as an electron but opposite charge. It has a very short lifetime as it quickly reacts with an electron to produce a pair of gamma rays, which are emitted in diametrically opposite directions. The energy of each gamma ray is always 511 keV.
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pos·i·tron (pozґĭ-tron) [positive electron] the antiparticle of the electron, a positive electron; a particle having the mass of the electron but a positive electric charge. Symbol e+.Medical dictionary. 2011.