Segr癡 working on proofs of book on Enrico Fermi. Emilio Gino Segr癡 (February 1, 1905 - April 22, 1989) was an Italian-American physicist. From 1936-38 he was Director of the Physics Laboratory at the University of Palermo. In 1938, Mussolini's fascist government passed anti-Semitic laws barring Jews from university positions. The Berkeley Radiation Lab offered him a job as a Research Assistant. At Berkeley, he helped discover the element astatine and the isotope plutonium-239, which was later used to make the Fat Man atomic bomb dropped on Nagasaki. From 1943-46 he worked at the Los Alamos National Laboratory as a group leader for the Manhattan Project. In 1944, he became a naturalized citizen of the USA. Returning to Berkeley, he became a professor of physics and of history of science, serving until 1972. Segr癡 and Owen Chamberlain were co-heads of a research group at the Lawrence Radiation Laboratory that discovered the antiproton, for which the two shared the 1959 Nobel Prize in Physics. In 1974 he returned to the University of Rome as a professor, but served only a year before reaching the mandatory retirement age. He died in 1989 of a heart attack at the age of 84.