Emilio Segrè

Italian-American nuclear physicist and radiochemist best known for his 21 September 1955 discovery with Owen Chamberlain of the antiproton, the unstable negatively charged proton that exists as the antiparticle of a proton. This helped to support Paul Dirac's theory of antimatter, and earned Chamberlain and Segrè the Nobel Prize for Physics in 1959. Segrè also discovered the elements technetium and astatine.

In 1937 Segrè discovered technetium, the first man-made element. In 1938 Segrè was fired from his position as Administrator of the Physics Laboratory at the University of Palermo because Mussolini had deemed that Jewish scientists should not be allowed to hold such posts. He then migrated to America, where he was a group leader in the Manhattan Project. In 1944 he made the crucial discovery that plutonium made in a nuclear reactor has higher levels of the isotope plutonium-240 than plutonium produced in a cyclotron.

Emilio Segrè died from a heart attack on 22 April 1989 at age 84 in Lafayette, California.