Segrè, Emilio Gino

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SEGRÈ, EMILIO GINO (1905–1989), nuclear physicist and Nobel Prize laureate. Segrè, who was born in Tivoli, Italy, studied at Rome University, where he later assisted Enrico Fermi in research on the use of neutrons as missiles to break up the uranium atom. He conceived the idea that an element having the atomic number 43, which theory had shown must exist, might be produced by neutron bombardment. The discovery of this element had been reported ten years earlier, but not confirmed. During a visit which he paid to the University of California in 1937, Segrè was given a sample of molybdenum (the element with atomic number 42) which had undergone a process shown by J.R. *Oppenheimer to be the equivalent of neutron bombardment. Segrè analyzed this sample when he returned to Italy. He traced what had become of the radioactivity it had already lost and thereby located small quantities of element 43, which he called "technetium." In 1938, when racial legislation was introduced in Italy, Segrè emigrated to the U.S. His work at the University of California led to the synthesis of astatine, another hitherto undiscovered element. After World War ii, he participated in the search for an elementary particle known as the "antiproton," whose existence and nature were inferred from very advanced reasoning. In 1955 the team of Segrè and Owen Chamberlain reported on the formation of the antiproton. For this achievement, they shared the Nobel Prize for physics four years later (1959). The antiproton discovery was followed by studies of its properties and interactions, as well as those of the antineutron. He retired in 1972, but remained active, with traveling and writing taking up much of his time.

In the immediate postwar years Segrè edited an influential three-volume handbook on experimental nuclear physics. He served as chairman of the editorial board overseeing the publication of the collected papers of Enrico Fermi. In 1964 he authored a text on nuclei and particles and in 1970 a biography of Fermi. His lectures on the history of physics were made into two accessible books. His autobiography appeared posthumously in 1993. He also served for 20 years (1958–77) as editor of the Annual Review of Nuclear Science.


T. Levitan, Laureates: Jewish Winners of the Nobel Prize (1960), 103–7; Chemical and Engineering News, 37 (1959), 86f., 104f.

[J. Edwin Holmstrom /

Bracha Rager (2nd ed.)]