The antiproton is the antiparticle of the proton. Antiprotons are short-lived in nature, since any collision with a proton will cause both particles to be annihilated in a burst of energy. It was discovered in the year 1955 by Emilio Segre and Owen Chamberlain, for which they were awarded a 1959 Nobel Prize in Physics.
Their formation requires energy equivalent to a temperature of 10 million °C, and Big Bangs aside, this does not tend to happen naturally. However, at CERN, protons are accelerated in the Proton Synchrotron (PS) to an energy of 26 GeV, and then smashed into an iridium rod. The protons bounce off the iridium nuclei with enough energy for matter to be created. A range of particles and antiparticles are formed, and the antiprotons are separated off using magnets.
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