The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. The positron has an electric charge of +1, a spin of, and the same mass as an electron. When a low-energy positron collides with a low-energy electron, annihilation occurs, resulting in the production of two or more gamma ray photons (see electron-positron annihilation). The existence of positrons was first postulated in 1928 by Paul Dirac as a consequence of the Dirac equation. Positrons may be gene… (More on Positron)