born Feb. 1, 1905, Tivoli, Italy
died April 22, 1989, Lafayette, Calif., U.S.
Italian-born U.S. physicist.
He worked under technetium , the first man-made element not found in nature. While visiting California in 1938, he was dismissed from the university by the fascist government. He continued his research at the University of California at Berkeley, where he and his associates discovered the element astatine and the isotope plutonium-239, which he found to be fissionable. In 1955, using the new Bevatron particle accelerator, Segrè and Owen Chamberlain (b. 1920) produced and identified antiprotons, antiparticles having the same mass as protons but opposite electrical charge, setting the stage for the discovery of many additional antiparticles. The two men shared a 1959 Nobel Prize.